Turmeric and Curcumin Supplements and Spices Review

Find the Best Turmeric and Curcumin Supplements & Spices. Big Differences Discovered Among Brands -- Little Curcumin In Some.

Medically reviewed and edited by Tod Cooperman, M.D.

Last Updated: 11/24/2021 | Initially Posted: 09/15/2019Latest Update: Contaminated Turmeric

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Table of Contents

Summary

· What are turmeric and curcumin? Turmeric is a spice used for its flavor and orange-yellow color. Curcumin is one of several curcuminoid compounds found in turmeric that give turmeric its color and antioxidant and anti-inflammatory properties, making turmeric root powders and extracts useful as dietary supplements (see What It Is).

· What are the health benefits of turmeric? Small clinical studies suggest that curcumin from turmeric is helpful for indigestion, ulcerative colitis, rheumatoid arthritis and osteoarthritis, seasonal allergies and depression. Other compounds may also be active (see What It Does).

· How much turmeric should I take? The typical daily dose ranges from 500 mg to 2,000 mg of curcuminoids (most of which is curcumin) from turmeric extracts (see Dosage), which can often be as much as 95% curcuminoids. Turmeric powder in some supplements is similar to turmeric spice, which is only about 3% curcuminoids, i.e., one teaspoon of turmeric powder (about 5,000 mg) provides only about 150 mg of curcuminoids.

· How do forms of turmeric differ? Turmeric and curcumin are not well absorbed on their own and it's generally best to take turmeric/curcumin with food containing some fat in order to increase absorption. See Absorption and Bioavailability to learn about bioavailability enhancement with ingredients such as BCM-95, C3 (which includes the black pepper extract Bioperine), CurcuWin, Longvida, Meriva, NovaSol, and Theracurmin.

· What did CL's tests of turmeric find? As shown in the Results Table below, one supplement was found to contain just 82.7% of the curcuminoids expected by CL. Another supplement from a major brand provided just 10 mg of curcuminoids, far less than other brands, which often contained 100 mg or more.

· Best turmeric/curcumin supplement? Among supplements that passed testing, we identified our Top Pick for Supplements -- which provided curcumin at one of the lowest costs and includes a bioavailability enhancer to boost the amount of curcuminoids making it into your bloodstream (see Absorption and Bioavailability to learn about bioavailability enhancement with BCM-95, C3 -- which includes the black pepper extract Bioperine, CurcuWin, Longvida, Meriva, NovaSol, and Theracurmin. It's generally best to take turmeric/curcumin with food containing some fat in order to increase absorption. A Top Pick for Dogs was also selected.

· Best turmeric spice? We also purchased popular brands of turmeric spice, testing them for curcuminoid content, heavy metals (lead, cadmium and arsenic) and filth (e.g., insect fragments and mites). One product stood out for providing significantly more curcuminoids than other products -- as well as being less expensive and containing less filth -- and was chosen as our Top Pick for Spices. To get the most from turmeric spice, use it in a meal that contains fats or oils, as well as some black pepper.

· Turmeric/curcumin safety and side effects: Turmeric/curcumin supplements are generally safe, but gastrointestinal side effects may occur with higher doses and they can cause problems for people with gallbladder disease, kidney stones, or those taking blood-thinning or blood-sugar-lowering medications. Rarely, liver injury has been reported. One of the bioavailability enhancers commonly added can potentially affect a number of drugs (see Concerns and Cautions).

What It Is:

Turmeric is a spice used commonly as a food coloring, flavoring agent, and is a key ingredient in curry powders and mustards. Turmeric is used in Ayurveda (traditional East Indian medicine) for abdominal ailments and arthritis. The dried, powdered roots (or rhizomes) of the plant, Curcuma longa, are used medicinally. Most research has focused on compounds in turmeric called curcuminoids and, more specifically, on the compound curcumin, which gives turmeric its orange-yellow color and is the predominant curcuminoid in turmeric. The other two curcuminoids in turmeric are demethoxycurcumin and bisdemethoxycurcumin.

What It Does:

Many uses of turmeric relate to the antioxidant or anti-inflammatory activities of curcumin. The anti-inflammatory action might involve blocking cyclooxygenase-2 (COX-2), the target of non-steroidal anti-inflammatory drugs (NSAIDs) like Celebrex (celecoxib) and Motrin (ibuprofen). In in-vitro studies, curcumin has also been shown to inhibit certain pathogenic bacteria and viruses, as discussed below.

A critical analysis of research on curcumin extracts (as opposed to whole turmeric powder or extracts with a broader range of turmeric compounds) by experts in medicinal chemistry suggested that: 1) much of the activity of curcumin in laboratory experiments may be "false" and only due to its interference with tests; 2) regular curcumin lacks features common to useful medicines since it is poorly absorbed and unstable; and 3) several well-controlled clinical studies have failed to show clinical benefits with curcumin (Nelson, J Med Chem 2017). The analysis makes valid points -- studies to-date that have shown benefit have been small — but it avoids discussion of the potential for bioavailability-enhanced curcumin formulations that overcome absorption issues and are now the most commonly used types of curcumin supplements. 

Nevertheless, turmeric and curcumin have been studied, with varying success, for treating a wide range of conditions, as discussed below.

Gastrointestinal Uses:
Turmeric and curcumin have been evaluated for conditions ranging from simple indigestion to several forms of inflammatory bowel diseases.

Several small, short-term studies suggest that taking curcumin after meals or before bedtime may, over time, slightly to modestly reduce symptoms of indigestion (functional dyspepsia) such as stomach pain, bloating and gas. For example, a study in Thailand among 116 participants who took either 500 mg of turmeric or placebo four times daily for seven days found that 87% of the turmeric group reported improvement compared to 53% in the placebo group (Thamlikitkul, J Med Assoc Thai 1981). A second study in Thailand, among 132 men and women with moderate indigestion who took either 500 mg of curcumin (containing at least 5% curcuminoids) four times daily (after meals and at bedtime), the proton-pump inhibitor omeprazole (e.g. Prilosec) 20 mg once daily before breakfast), or a placebo (after meals), found that, after one month, those who took curcumin or omeprazole had similar, modest reductions in pain (average decreases of 17 points and 15 points, respectively, on a 47-point scale), and these decreases were statistically significant compared to placebo (average decrease 10 points), although not much greater. Those who took curcumin also had similar decreases in other symptoms, such as gas, bloating and nausea, as those who took omeprazole (average decrease of 8 points and 7 points, respectively, on a scale of 0 to 35), but these decreases were only statistically significant compared to placebo (average decrease 6 points) for those who took curcumin (Yongwatana, J Gastroenterol Hepatol 2021).

A study among 79 men and women (average age 42) in Australia with mild to moderate digestive symptoms such as reflux, indigestion, diarrhea, and constipation, found that taking 500 mg of a standardized turmeric extract formulated with a small amount of turmeric essential oils to improve bioavailability (Curcugen, by DolCas Biotech, LLC, which funded the study), providing 250 mg of curcuminoids, once daily with 8 oz. of water immediately before sleep for two months only slightly reduced the average overall symptom scores compared to placebo (an average reduction of 0.81 points vs a reduction of 0.47 points, respectively, on a 7-point scale), but there was no improvement in any specific symptoms (e.g., pain, reflux, diarrhea, indigestion, or constipation) compared to placebo (Lopresti, BMC Complement Med Ther 2021).

Ulcerative colitis, Crohn's disease, and other GI conditions:
Curcumin may be helpful for people with ulcerative colitis when taken in addition to standard medication (e.g., mesalamine, also known as 5-ASA), although results appear to vary depending on the curcumin formulation and dosage. In one study, 50 people with mild to moderate ulcerative colitis not responsive to mesalamine were given 1.5 grams of curcumin twice a day (3 grams per day of curcumin) or placebo for one month with continued mesalamine treatment. At week four, none of the patients who received placebo achieved remission, while a startling 53.8% of those receiving curcumin did. The curcumin used was Cur-Cure™ (Bara Herbs, Israel), a 95% pure curcumin preparation (Lang, Clin Gatroenterol Hepatol 2015). A study among 56 men and women in Iran with mild to moderate ulcerative colitis found that 80 mg of an enhanced-bioavailability "nanoparticle" formulation of curcumin (similar to Theracurmin) taken three times daily (240 mg per day) in addition to mesalamine for one month modestly decreased urgency of bowel movements and improved self-reported well-being, but did not decrease blood in the stool or colitis-related skin ulcers compared to mesalamine alone (Masoodi, J Cell Biochem 2018).

One gram of curcumin taken twice daily in addition to mesalamine or sulfasalazine for six months helped maintain remission from ulcerative colitis compared to standard medications plus placebo (Hanai, Clin Gastroenterol Hepatol 2006), but a lower dose (450 mg of curcumin daily) did not improve remission rates or improve mucosal healing compared to placebo in men and women with active ulcerative colitis taking mesalamine (Kedia, World J Gastrointest Pharmacol Ther 2017).

A very small pilot study suggests a benefit with curcumin in treating ulcerative proctitis and Crohn's disease (Holt, Digestive Diseases and Sciences 2005). However, a double-blind, randomized trial found that curcumin (3,000 mg of a 95% pure extract providing 2,850 mg of curcuminoids) taken daily for six months was no more effective than placebo in preventing recurrence of Crohn's disease in adult patients who had recently undergone a bowel resection and were taking the immunosuppressant medication (azathioprine). In fact, a significantly higher proportion (55%) of those receiving curcumin had a severe recurrence compared to those receiving the placebo (26%) (Bommelaer, Clinical Gastroenterology and Hepatology 2019).

The results of human studies using turmeric for treating gastric or duodenal ulcers conflict. At least two studies found no benefit while a third found that turmeric improved symptoms. Additionally, while some animal research suggests that turmeric might help prevent ulcers, other animal research suggests that turmeric might increase the risk of ulcers.

A preliminary study in five people with familial adenomatous polyposis (a genetic disorder causing hundreds of intestinal polyps and eventually colorectal cancer) suggested that curcumin might cause regression of polyps in such people, and such is the case with other non-steroidal anti-inflammatory drugs. However, a 12-month clinical study in which patients were given 1,500 mg of pure curcumin twice daily or a placebo found no significant difference in the mean number of polyps or polyp size between the two groups. Possibly explaining the different outcomes of the studies, the researchers noted the earlier, positive, study used a lower total dose of curcumin (480 mg given three times daily) but it included black pepper extract to increase bioavailability as well as quercetin (20 mg per dose) (Cruz-Correa, Gastroenterology 2018).

Arthritis:

Rheumatoid arthritis:
Curcumin can help treat symptoms of rheumatoid arthritis -- although it is not superior to non-steroidal anti-inflammatory drugs.

As noted in a meta-analysis of several clinical studies, there is compelling evidence that curcumin (about 1,000 mg per day) can be effective in treating symptoms (mainly pain and inflammation) of osteoarthritis and rheumatoid arthritis, although larger studies are needed to confirm these findings before a definitive recommendation can be made (Daily, J Med Food 2016). More details regarding the use of curcumin in each type of arthritis are below.

Two small studies have shown that curcumin may reduce symptoms of rheumatoid arthritis including joint swelling and stiffness and walking time. In one study, 1,200 mg of curcumin reduced symptoms, but not as well as the non-steroidal anti-inflammatory drug (NSAID), phenylbutazone (Deodhar, Indian J Med Res, 1980). In another study, 500 mg twice daily of a bioavailability-enhanced curcumin product (BCM-95, Biocurcumin) was comparable to a low dose (50 mg) of diclofenac (an NSAID) twice daily, after 8 weeks. Symptoms were reduced by about 40% from the beginning to the end of the study. Combining the curcumin and diclofenac was no more effective than either one alone (Chandran, Phytother Res 2012). A weakness of this study is that there was no placebo control group. (Note: The curcumin used in this study, BCM-95 is listed as an ingredient in Life Extension Advanced Bio-Curcumin and Terry Naturally CuraMed tested in this Review.)

A small, 90-day study in India found a highly bioavailable formulation of curcumin to greatly reduce pain and inflammation in people with rheumatoid arthritis. Twice-a-day after meals, patients took a placebo or 250 mg or 500 mg of the curcumin formula (AcuminTM also called Cureit, from Aurea Biolabs, India, which is 50% curcuminoids and, apparently, 10 times more bioavailable than regular curcumin) (Amalraj, J Med Food 2017). Although improvements were noted in biochemical markers of inflammation relative to placebo, it was not mentioned whether the improvements in symptoms were statistically significant relative to placebo: Due to small sample sizes in the study, they may not have been. This, and the fact that most of the study authors were employed by the product manufacturer, raise doubts about the importance of the findings. (This ingredient does not appear to be in any of the products tested in the Review below).

Osteoarthritis:
Several short-term (6 to 12 week) studies have shown generally modest benefit with different turmeric formulations.

A small placebo-controlled study of people with mild to moderate osteoarthritis of the knee found treatment with curcuminoids to be helpful. Six weeks of daily treatment with 1,500 mg of a curcuminoid complex resulted in significantly greater reductions in the severity of osteoarthritis symptoms than with placebo, with a particular reduction in pain and an improvement in physical function. Reports of stiffness were reduced in both the treatment and placebo groups, although not significantly more so in the treatment group (Panahi, Phytother Res 2014). Those receiving curcumin were able to reduce their use of anti-inflammatory drugs by 84% during the study -- significantly more than the 19% reduction among those in the placebo group. The curcumin used in the study was taken three times each day as a capsule containing 500 mg of curcuminoids as C3 complex® including 5 mg of Bioperine®, a bioavailability enhancer. This ingredient, C3 complex®, is found in two products listed below in this review: Doctor's Best High Absorption Curcumin and Root2 Turmeric Extract Curcumin C3 Complex, although the concentration of Bioperine® is lower in these products (about 2.5 mg rather than 5 mg per 500 mg of C3 complex®). 

The BCM-95 version of curcumin (taken as 500 mg capsules of CuraMed, each with 333 mg curcuminoids, as in Terry Naturally CuraMed and other products in this Review) was also found to modestly reduce pain-related symptoms of knee osteoarthritis as compared to placebo (which also showed improvement) in a 12-week study in Armenia, although it was somewhat more effective in improving physical performance when taken combined with a Boswellia extract (as Curamin — 350 mg curcuminoids and 140 mg boswellic acid, not tested in this Review, but found in Terry Naturally Curamin). The capsules were taken three times a day (Haroyan, BMC Compl Alt Med 2018).

A study in Belgium among 101 men and women with moderate knee osteoarthritis who took either 187 mg or 280 mg daily of turmeric root extract (90% curcumin formulated with polysorbate 80 to enhance absorption), or placebo, daily for three months all had modest improvements in self-reported measures of pain and mobility, but improvements were greater in those who took the extract (Flexofytol, from Tilman, which funded the study, but is not available in the U.S.). Pain decreased by 8 points (on a scale from 1 to 100) in those who took placebo, compared to decreases of 29.5 and 36.5 points, respectively, in those who took the low and higher doses of turmeric extract. Statistically, there was no difference in efficacy between the low and higher doses, although those who took the higher dose reported more adverse effects, such as abdominal discomfort and diarrhea, than those who took the lower dose or placebo. The extract was divided into two doses with meals (Henrotin, Arthritis Res Ther 2019).

There is only slight additional benefit from curcumin in people already taking an anti-inflammatory drug for osteoarthritis. A study evaluated the effect of daily curcumin (500 mg of a 95% curcuminoid extract) or a placebo (talc) in patients also given the anti-inflammatory drug diclofenac (50 mg/day) and omeprazole (20 mg/day, given to reduce gastric side effects of diclofenac). Not surprisingly, at two months both groups reported major improvements in joint pain, stiffness and function, but the curcumin group showed only slightly better improvement in pain and function, e.g., the pain score fell from 15 to 9.5 in the curcumin group and from 15 to 10.2 in the placebo group. The curcumin group had greater decreases in markers of oxidative stress, but not in levels of IL-1 beta, a marker of inflammation. Neither group showed knee joint improvements on X-ray. (Srivastava, Inflammopharmacol 2016).

Interestingly, taking curcumin alone or in combination with fish oil did not reduce joint pain in a placebo-controlled study of sedentary, obese men and women with mild, chronic osteoarthritis pain in the knees, lower back or shoulders (Kuszewski, Rheumatol Adv Pract 2020). [Note: The same study found no benefit with the addition of curcumin for increasing blood flow to the brain.]

Although most arthritis studies have focused on curcumin, one study suggested that other constituents in turmeric may have a role. This study used a turmeric extract (NR-INF-02 "Turmacin®," Natural Remedies, India, 500 mg twice daily) that contained turmeric polysaccharides but no curcumin. The extract was found to perform better than placebo and better than chondroitin sulfate among people with osteoarthritis (Madhu, Inflammopharm 2013).

Another study that evaluated turmeric polysaccharides with curcuminoids found modest improvement in pain but no reduction in swelling. The study involved 69 people (average age 62) with symptomatic knee osteoarthritis and confirmed effusion/synovitis (i.e., swelling/fluid collection in the joint) who took either 1,000 mg of turmeric extract (providing 800 mg of polysaccharides and 200 mg of curcuminoids) or placebo daily. After 12 weeks, those taking turmeric extract reported slightly less knee pain, but there was no significant reduction in swelling/fluid in the joint based on MRI images compared to the placebo group. The study was partially funded by the company that manufactured the extract (Turmacin Plus, Natural Remedies). Some, although not all, people in this study also used pain relievers, including anti-inflammatory drugs, or supplements for arthritis, and this may have impacted the results (Wang, Ann Intern Med 2020).

Muscle Soreness and Recovery After Exercise:
Several studies have evaluated formulations of curcumin on muscle function, recovery, and soreness after exercise. Although some studies report a benefit, others have not and the usefulness of curcumin in muscle recovery and soreness remains questionable. At best, if taken for a few days before intense exercise, curcumin may slightly reduce resulting inflammation and, if taken after exercise, it may reduce muscle damage and soreness.

A small, placebo-controlled study in young healthy men found that 90 mg of a bioavailability-enhanced curcumin formula (Theracurmin, from Theravalues Corp., which funded the study) taken with breakfast and dinner for seven days before a single intense session of eccentric resistance arm exercise slightly reduced one blood marker of inflammation 12 hours after exercise, but did not decrease muscle soreness or improve recovery compared to placebo at any time during the seven days after exercise. However, when the same dose of curcumin was taken for seven days after the exercise session, a significant reduction in muscle soreness as well as improved muscle strength and range of motion were observed starting about 3 to 6 days after the exercise session. Taken after exercise, curcumin also reduced blood levels of creatine kinase (a marker of muscle damage), but did not reduce markers of inflammation (Tanabe, Scand J Med Sci Sports 2018).

Other studies that have suggested a benefit include two that used a bioavailability-enhanced curcumin, Meriva: One gave 20 healthy young men 200 mg of curcumin (from 1 gram of Meriva) at breakfast and dinner for four days; they experienced significantly less soreness in their front thighs 48 hours after intense treadmill exercise (on the third day of treatment) than men given placebo (Drobnic, JISSN 2014). The other involved 50 young male rugby players with muscle and/or joint pain due to overuse or injury who were given Algocur (containing 1 gram of Meriva) or traditional anti-inflammatory medication for up to 10 days. Both groups reported similar decreases in self-reported pain and improvements in physical function. However, it is not possible to draw conclusions from this study because there was no placebo-control and those taking curcumin were permitted to take anti-inflammatory drugs as needed (Di Pierro, Eur Rev Med Pharmacol Sci 2017).

Another small, placebo-controlled study in young healthy men found that 2,500 mg of curcumin taken twice daily (a total daily dose of 5,000 mg providing roughly an equivalent amount of curcuminoids) 2 days prior to, and 3 days after, intense leg exercise moderately reduced leg pain during subsequent exercise (24 and 48 hours later), indicating a reduction in delayed onset muscle soreness (DOMS). Effects on biochemical markers of inflammation, however, were inconclusive (Nicol, Eur J Appl Physiol 2015). A small study among healthy young men and women given 200 mg of curcuminoids (from 1 gram of CurcuWIN) daily for two months showed significantly reduced thigh muscle soreness 24 hours after muscle damaging exercise compared to placebo; however, there was no significant reduction in soreness one hour after exercise, nor 2 and 3 days after exercise, compared to placebo. The curcuminoids reduced a marker of muscle damage (creatine kinase) two days after the exercise, but did not reduce other markers of inflammation, compared to placebo. A lower dose (50 mg of curcuminoids from 250 mg CurcuWIN) reduced muscle damage, but did not significantly decrease soreness (Jager, FASB J 2017).

A study among 22 healthy, young men and women found that taking 500 mg of curcumin standardized to 95% curcuminoids (Curcumin 95, Jarrow Formulas -- providing 475 mg of total curcuminoids from Curcumin C3 Complex) twice daily starting six days before a single session of high-intensity exercise and continuing for three days afterward modestly decreased muscle soreness up to three days after exercise compared to placebo. In addition, while the placebo group lost muscle power 7 days after exercise, the curcumin group maintained it. However, curcumin did not reduce blood markers of muscle damage or inflammation compared to placebo. The study was partially funded by the McCormick Science Institute (Hillman, J Diet Suppl 2021).

Studies that failed to show a benefit include one in which a daily dose of 400 mg of a curcumin formula containing 80 mg curcumin plus fats to enhance absorption (Longvida® Optimized Curcumin) was given to healthy young men and women for two days before and four days after leg press exercises (designed to induce muscle damage). The curcumin did not reduce muscle soreness compared to placebo, but it did result in somewhat smaller increases in biological markers of inflammation (McFarlin, BBA Clinical 2016). A more recent, placebo-controlled study in France gave athletes 6,000 mg of curcumin plus 60 mg of the bioavailability enhancer piperine daily (divided into 3 doses) for two days before and after exercise-induced muscle damage. The curcumin did not limit muscle damage or soreness and only limited loss of power in one of several exercises (sprinting) (Delecroix, J Sports Sci Med 2017).

Memory, Cognition, and Alzheimer's Disease
Curcumin has shown some short-term beneficial effects on cognition (thinking and memory) but longer-term studies have shown mixed results.

A small, but well-controlled study found that daily supplementation after breakfast with 400 mg of a patented curcumin formula containing 80 mg curcumin plus fats to enhance absorption (Longvida® Optimized Curcumin — Longvida funded the study) significantly improved some aspects of cognitive function and fatigue in healthy men and women ages 60 to 85. One hour after ingestion of the first dose, scores on a subtraction test improved by 16%, which was significantly more than the 2% increase with placebo; however; the effect was brief — when the subjects were retested 3 hours later no benefit was found. After 4 weeks of daily supplementation at the same dose, scores among those taking curcumin improved by 17% (vs. 3% with placebo) and fatigue was reduced by 11% (vs. 4 % with placebo). While these results are intriguing, it must be noted that no benefits were found on tests of word and picture recall (Cox, J Psychopharm 2014). However, a longer study funded by the U.S. NIH using a much higher dose of the same curcumin formula did not find benefit. In the study, 39 healthy men and women ages 45 to 74 took 2,000 mg of Longvida providing 400 mg of curcumin every morning on an empty stomach for three months; there was no significant improvement on measures of cognitive function, fatigue, or motor function such as hand grip, knee strength, walking/mobility, compared to placebo. It should be noted that, unlike the earlier study, Longvida was taken without food, which may have reduced its absorption — although Longvida is made with fats claimed to improve its absorption (Santos-Parker, Nutr Healthy Aging 2018). Another study with Longvida (providing 80 mg of curcumin taken with breakfast and, again, with dinner), showed that, after 16 weeks, it did not improve blood flow to the brain in older individuals (ages 50 to 80) in Australia who were sedentary and obese. The placebo-controlled trial also failed to show benefits with regard to blood pressure and cholesterol levels and there was no benefit from adding Longvida it to fish oil supplementation (1,000 mg of DHA and 200 mg EPA taken with breakfast and dinner). The fish oil alone, however, showed some cardiovascular benefits, such as reductions in heart rate and triglycerides and an increase in HDL cholesterol, as well as reduced stiffness of the cerebral arteries but no significant effect on blood flow to the brain (Kuszewski, Nutr, Met Cardio Dis 2020).

Another small, but placebo-controlled study found that taking a capsule with 1,000 mg of turmeric powder (about 1/4 teaspoon) with a nutritionally-bland breakfast resulted in improvements in short-term memory in people aged 60 years or older who were newly diagnosed with pre-diabetes. When tested six hours after taking the turmeric, scores were 2.9 (out of a possible 3.0) on a test to recall numbers in sequence, compared to 2.6 prior to turmeric. Scores did not improve among those who received placebo. Interestingly, turmeric had no effect on blood sugar or insulin levels. The study also evaluated the effects of taking 2 grams of cinnamon, which had no effect on any of the parameters measured (Lee, Asia Pac J Nutr 2014).

A long-term study in Australia among older adults (mainly in their 60s) with normal cognitive function found that taking high-dose curcumin daily had no beneficial effect on cognitive function, nor on mood or general quality of life, compared to treatment with placebo over a 12-month period. The curcumin used was BCM-95 CG (Biocurcumax — 88% total curcuminoids) given as a 500 mg capsule taken 3 times a day after meals with water. A fairly high percentage (26%) of those taking curcumin withdrew from the study due to side effects — most of which were gastrointestinal in nature, compared to only 4% of those taking placebo. According to the researchers, the rate of side effects would likely have been lower had the dose been gradually ramped-up rather given at the full amount at the beginning of the study (Rainey-Smith, Br J Nutr 2016).

A double-blind study among 40 older adults with normal cognition or mild cognitive impairment found that taking 90 mg of an enhanced bioavailability curcumin formula (Theracurmin, which is 30% curcumin, from Theravalues Corp. which funded the study) twice daily for 18 months modestly improved measures of short-term memory, verbal memory and attention compared to placebo. About 19% of participants in the curcumin group reported gastrointestinal side effects (transient abdominal pain, gastritis, or nausea) compared to 10.5% of those in the placebo group. Those in the placebo group showed slight increases (on PET scans) in amyloid beta plaque and tau tangles in the hypothalamus and these increases were not found in the curcumin group, but no other significant differences between the groups were found in other parts of the brain. Although such changes are associated with Alzheimer's disease, the value of these findings is unclear (Small, Am J Geriatr Psychiatry 2017). Several authors of the study have a financial interest in a tracer agent used in the PET scan and have been warned by the FDA for claiming it can be used to diagnose neurological conditions.

Laboratory and animal studies have shown curcumin inhibits several biological and chemical processes in brain cells associated with the development of Alzheimer's disease, including inflammation, oxidative stress and the formation and accumulation of amyloid-beta proteins (which form brain plaques associated with Alzheimer's). Animal studies also suggest curcumin may work similarly to acetylcholinesterase inhibitors, a class of drugs (such as donepezil (Aricept) and galantamine (Razadyne)) that may slow the progression of Alzheimer's symptoms. In mouse models of the disease, curcumin given orally appears to reach the brain and reduce oxidative damage and memory impairment (Frautschy, Neurobiol Aging 2001). However, results have been less promising in clinical trials of curcumin in people with Alzheimer's. For example, a preliminary study found that curcumin given to Alzheimer's disease patients did not significantly improve mental functioning compared to placebo (Baum, J Clin Psychopharm 2008). Another study in people with mild to moderate Alzheimer's found that curcumin did not improve cognitive function or decrease amyloid-beta (as measured in cerebrospinal fluid) compared to placebo (Ringman, Alzheimers Res Ther 2012). Curcumin (100 mg of curcumin from turmeric powder capsules) taken daily for three months has been reported to reduce agitation, anxiety and irritability in three people with severe Alzheimer's disease who were also taking an acetylcholinesterase inhibitor (Nozomi, Ayu 2012). In a review of the evidence for curcumin and Alzheimer's disease, the researchers concluded that, to date, studies in people "have not been able to generate the anticipated benefits of curcumin," noting that this may be due, in part, to the low bioavailability and absorption of curcumin and the severity of disease progression in the people who participated (Goozee, Br J Nutr 2015).

Interestingly, in adults with insulin resistance, a bioavailability-enhanced form of curcumin appeared to cause a decrease in blood levels of amyloid-beta proteins (see Insulin Resistance and Diabetes below).

Depression
Curcumin may help treat depression, although effects may take two to three months. A small but controlled, 8-week study among people with major depression found partial support for antidepressant and anti-anxiety effects of curcumin. Patients received either placebo or curcumin (500 mg of BCM-95) twice daily and remained on pharmaceutical antidepressants during the study. At four weeks into treatment, depressive symptoms had improved equally for both groups, but from weeks 4 to 8 curcumin was significantly more effective than placebo in improving depressive symptoms. Greater efficacy was noted among individuals with atypical depression. One of the ways curcumin may affect depression, according to the researchers, is through an immune-inflammatory pathway (Lopresti, J Affect Disorders 2014). A larger, more recent study among people with major depression (about half of whom were taking a prescription antidepressant) found that a lower dose (250 mg twice daily) of BCM-95 taken for three months significantly reduced symptoms of depression, as well as anxiety, compared to placebo, and was as effective as the higher dose of 500 mg twice daily (Lopresti, J Affect Disorders 2016). As in the previous study, curcumin's effects became significant compared to placebo after the first 4 weeks, and greater efficacy was found in those with atypical depression.

In addition, a study in Thailand showed that curcumin supplementation was more effective than placebo in improving symptoms of depression in adults who were already taking an antidepressant (fluoxetine (Prozac), sertraline (Zoloft), trazodone (Desyrel) or mianserin (Tolvon)). The curcumin was given as a capsule containing 250 mg curcuminoids (192.5 mg of curcumin, 42.5 mg of demethoxycurcumin and 15 mg of bisdemethoxycurcumin) taken twice daily (before breakfast and dinner) for the first week. The dose was increased by 250 mg per week for three weeks, and then maintained at a dose of 1,500 mg per day for eight more weeks. Compared to placebo, significant improvements in symptoms of depression occurred 12 weeks after beginning supplementation with curcumin (Kanchanatawan, Neurotox Res 2018).

Insulin Resistance and Diabetes
In healthy people, curcumin may lessen increases in blood sugar and insulin after eating. It may also decrease the risk of developing prediabetes in people who are overweight, and have modest benefits in people with insulin resistance or prediabetes. However, there is mixed evidence as to whether curcumin supplementation is beneficial in people with type II diabetes, and the effects may be very modest, at best.

Taking curcumin with a meal can minimize the increase in blood sugar and insulin levels that occurs after eating. A small study in Australia among 15 healthy young men and women (average age 26) found that taking 180 mg of curcumin (from two tablets of the bioavailability-enhanced curcumin formulation Meriva) immediately before consuming breakfast (toast, peanut butter and chocolate milk, providing 56 g carbohydrate, 22 g fat and 21 g protein) reduced the increase in blood sugar and insulin levels one hour after the meal by 61% and 26%, respectively, compared to placebo. Interestingly, taking the same amount of curcumin with fish oil (1.2 grams of fish oil providing a total of 240 mg EPA + 860 mg DHA) had the same effect on insulin levels as curcumin alone but slightly blunted curcumin's effect on blood sugar (Thota, Sci Rep 2018).

The same researchers subsequently conducted a 3-month study among 29 men and women (average age 52) with insulin resistance. They found that taking 1,000 mg of bioavailability-enhanced curcumin (Meriva) providing 180 mg of curcumin daily, significantly reduced insulin resistance compared to placebo (- 0.3 decrease in HOMA2-IR vs. a slight increase of 0.01). The curcumin also reduced blood serum levels of two compounds (glycogen synthase kinase-3, known as GSK-3, and islet amyloid polypeptide, known as IAPP), which are associated with the development of both diabetes and Alzheimer's disease (Thota, Nutrients 2020).

However, in people with type II diabetes, curcumin supplementation appears to have only a slight benefit, at best. A study in Japan among 33 men and women with impaired glucose tolerance or non-insulin dependent type II diabetes found that 90 mg of a bioavailability-enhanced curcumin formulation (Theracurmin, Theravalues Inc.) taken twice daily (after breakfast and dinner — a total of 180 mg Theracurmin, providing 54 mg of curcumin per day) for six months did not lower HbA1c (a measure of blood sugar over time) compared to placebo. Theravalues supplied the Theracurmin but did not fund the study (Funamoto, J Diabetes Res 2019). A study in Brazil among 61 men and women (average age 62) with type II diabetes who were not taking insulin found that those who took one capsule containing 500 mg of dry curcumin extract (standardized to contain 90% curcumin plus 5 mg of piperine) once daily on an empty stomach for 4 months had a slight but statistically significant decrease in HbA1c, but no improvements in fasting blood sugar, insulin levels, or HOMA-IR (a measure of insulin resistance) compared to placebo (Neta, Int J Food Sci Nutr 2021).

Preliminary research shows that, taken over a longer period of time, curcumin may lower the chances of prediabetes (blood sugar levels somewhat higher than normal) advancing to actual diabetes. A study of middle-aged, slightly overweight individuals in Thailand (Chuengsamarn, Diabetes Care 2012) found that over nine months, none of the 97 subjects randomized to daily treatment with curcumin (1.5 grams of curcuminoids/day in 2 divided doses) became diabetic, but 19 of 104 subjects receiving a placebo did. Curcumin appeared to boost activity of the insulin-secreting cells in the pancreas.

Weight Loss:
A review of 11 randomized, placebo-controlled studies among adults with conditions such as pre-diabetes, obesity, metabolic syndrome, or non-alcoholic fatty acid liver disease concluded that curcumin had a modest but significant effect in reducing body weight and BMI (body mass index). On average, study participants lost 2.5 lbs. of bodyweight, based on studies tending to be 3 to 12 weeks in duration. Curcumin was also found to reduce waist circumference (by about 1 to 1.5 inches), but only in people who were overweight taking at least 1,000 mg per day of curcumin for at least eight weeks (Mousavi, Crit Rev Food Sci Nutr 2018).

Other Uses:
A small study in Brazil among children and adolescents with persistent asthma of generally moderate severity who were taking traditional asthma medications found that daily supplementation with curcumin for six months decreased nighttime awakenings and use of short-acting inhalers, and improved disease control compared to traditional treatment plus a placebo. The curcumin was given twice daily in capsules; each capsule contained 250 mg of root powder (including 11 mg of curcumin and 2 mg of demethoxycurcumin) and the daily dose for each child varied by weight (about 30 mg per kg of bodyweight per day). Approximate daily dosages by age were: 500 mg powder (20 mg curcuminoids) (7 - 10 yrs); 750 mg powder (30 mg curcuminoids (11 - 14 yrs), and 1,000 mg powder (40 mg curcuminoids) (15 - 18 yrs) (Manarin, J Ethnopharmacol 2019).

A pilot study suggests that curcumin can reduce nasal symptoms associated with seasonal allergy (allergic rhinitis). In this study, more than 200 people in China with a history of seasonal allergy took capsules containing 500 mg of curcumin (ORGANIKA Health Products, Canada) or a placebo (colored starch) daily for two months. Over this period there were significant improvements in sneezing, runny nose, and nasal congestion among those given curcumin, with the average total symptom score falling from 8 (out of a possible 12) down to 2.8, while there were no significant changes in the placebo group. Curcumin was also found to affect levels of certain inflammatory mediators, including decreases in interleukin-4 and TNF-alpha (Wu, Ann Allergy Asthma Immunol 2016).

Although preliminary studies suggest that curcumin may help people with chronic anterior uveitis (an autoimmune disease of the eye that causes symptoms such as redness, pain, light sensitivity and blurred vision), this has not been proven in a well-controlled study. For example, a study in Italy found that a tablet containing 600 mg of Meriva taken twice daily in addition to standard treatments (steroids, immune-suppressants, and/or eye drops) reduced symptoms of eye discomfort within 4 to 6 weeks and, after one year, 42% of patients reported reductions symptoms such as eye pain, blurring of vision and redness. The average number of relapses decreased from 275 per year prior to supplementation to 36 during supplementation. However, there was no placebo group, so conclusions cannot be drawn from this study. The researchers noted that the results suggest curcumin might be beneficial for other inflammatory eye conditions such as dry eye (Pia, Clin Ophthalmol 2010). Laboratory and animal studies also suggest a potential benefit for dry eye but, there are no published efficacy studies in people. [Note: Interestingly, a CL member reported experiencing dry eye with taking Meriva].

There are anecdotal reports of curcumin being given to treat psoriasis, an autoimmune disease. However, a clinical trial with a curcuminoid complex showed a low response rate (Kurd, J Am Acad Dermatol, 2008).

There is mixed evidence on whether turmeric and curcumin can lower cholesterol. A review of studies of people at risk for cardiovascular disease indicated that turmeric and curcumin can lead to modest improvements by lowering elevated LDL "bad" cholesterol and triglycerides -- although they do not help raise HDL "good" cholesterol or lower total cholesterol levels. Curcumin formulations with enhanced bioavailability seemed to be more effective than turmeric powder, particularly with regard to lowering triglycerides (the review did not identify ideal dosage or formulations) (Qin, Nutr J 2017). An earlier review failed to find a beneficial effect on cholesterol levels from turmeric or curcumin, although that review did not include studies of products with enhanced bioavailability (Sahebkar, Clin Nutr 2014).

A study in Australia among older adults with high cholesterol levels (averaging 254 mg/dL total cholesterol and 169 mg/dL LDL) found that adding 1,000 mg of bioavailability-enhanced curcumin (Meriva -- providing 200 mg of curcumin) each day to 25 grams of a phytosterol-enriched fat spread (Logicol Original -- providing 2 grams of phytosterols) daily for one month resulted in average decreases in total and LDL cholesterol of 11% and 14.4%, respectively, as compared with decreases of 4.8% and 8.1% with only the phytosterol. Those who took only the curcumin had slight but non-significant decreases in total or LDL cholesterol (Ferguson, Metabolism 2017).

Curcumin has been shown to suppress proliferation of a wide variety of cancer cell types in the laboratory, but research showing clear benefit in people is limited.

A study of 64 adult smokers found that taking 4 grams of pure curcumin powder for 30 days reduced the number of aberrant crypt foci (an early change in the colon that might lead to colon cancer) by 39%. Test results indicated that this activity was achieved via absorption and circulation of curcumin through the blood stream, rather than direct effects of curcumin in the colon (Carroll, Cancer Prev Res Phila 2011).

A study in Australia among 18 people with monoclonal gammopathy of undetermined significance (MGUS) or smoldering multiple myeloma (SMM), both of which are considered to be precursors to myeloma (a bone marrow cancer of white blood cells), showed that taking 8 grams of curcumin daily for 3 months decreased serum free light-chain ratio, a risk factor for disease progression, by about 37% compared to baseline in people with abnormal free light-chain ratio. However, it is unclear if this benefit reduces the percentage of patients who progress to myeloma compared to what occurs using the standard "watch and wait" strategy. The curcumin used in this study was a "C3" curcuminoid mixture supplied by Sabinsa Corp. Each 4-gram dose provided 3,600 mg of curcumin, 320 mg of desmethoxycurcumin, and 80 mg of bisdesmethoxycurcumin. This mixture is similar to C3 complex® found in two products listed below in this review: Doctor's Best High Absorption Curcumin and Root2 Turmeric Extract Curcumin C3 Complex, although these products also include Bioperine to improve absorption (Golombick, Am J Hematol 2012).

In another small study in people with myeloma, taking 4 and 8 grams of curcumin daily for up to one year significantly reduced levels of certain inflammatory markers (such as COX-2) and a protein that promotes myeloma tumor growth (NF-kB), although it did not result in clinical improvements (Vadhan-Raj, Blood 2007). However, it has been reported that a 57-year-old woman with stage 3 myeloma who was no longer responding to traditional treatment began taking a daily dose of 8 grams of curcumin with Bioperine (dose not given) and once-weekly hyperbaric oxygen therapy and, during the next five years (up until the publication of the report), her myeloma remained stable with blood cell counts returning to normal range and maintaining a good quality of life (Zaidi, BMJ Case Reports 2017).

In a study of 21 patients with pancreatic cancer treated with 8 grams of curcumin daily, only two patients appeared to show a positive biological response (i.e., reduced progression or regression of cancer). The curcumin used in this study provided the same ratio of curcumin, desmethoxycurcumin, and bisdesmethoxycurcumin as the Golombick study above (Dhillon, Clin Cancer Res 2008).

A study in France among 44 men with metastatic castration-resistant prostate cancer who were receiving chemotherapy (docetaxel) and glucocorticoids (prednisone or prednisolone) found that taking 6,000 mg of curcumin daily (in divided doses taken in the morning, at lunchtime and in the evening) for seven days starting four days before each three-day chemotherapy treatment for six months did not improve progression-free or overall survival, PSA response rate or quality of life compared to the same medical therapy plus a placebo (Passildas-Jahanmohan, Cancer Med 2021).

One small clinical study in healthy, sedentary postmenopausal women found that a daily dose of 150 mg (from six 25 mg pills) of a branded curcumin ingredient (Theracurmin, Theravalues Corporation), taken for 2 months significantly lowered systolic blood pressure, but not diastolic blood pressure, compared to placebo. (Akazawa, Nutr Res 2012). The decrease in systolic blood pressure (about 5 points) was similar to that measured in women who did not take curcumin but participated in an aerobic exercise program at least 3 days per week for the duration of the study. The study does not note whether the six pills were taken together or divided throughout the day, or if they were taken with food. Curcumin has also been found to reduce systolic blood pressure in lupus patients with kidney nephritis (inflammation) taking corticosteroid and/or anti-hypertensive medications. A dose of 500 mg of turmeric (containing 22.1 mg curcumin) taken with each meal (a total daily dose of 66.3 mg curcumin) was found to significantly reduce systolic blood pressure after 3 months compared to placebo (Khajehdehi, J Renal Nutr 2012).

In people with non-alcoholic fatty liver disease (NAFLD), several short-term studies in Iran found that supplementation for two months with enhanced bioavailability curcumin formulations providing 70 mg to 200 mg of curcumin daily improved liver health, significantly lowering levels of certain liver enzymes (ALT and AST) and reducing liver size and/or liver fat content compared to placebo. These have included a study using an "amorphous dispersion preparation" of curcumin (Rahmani, Phytother Res 2016) and a study using a phytosomal formulation a complex of curcumin and soy phosphatidylcholine (Meriva) (Panahi, Drug Res (Stuttg) 2017). The most recent of these studies used 500 mg of curcumin with 5 mg of Bioperine (C3 Complex, Sami Labs) taken once daily for three months. This significantly decreased ALT, AST and ALP liver enzymes levels and disease severity scores, but did not decrease total or LDL cholesterol or improve measures of blood sugar or insulin control in men and women with mild to moderate NAFLD compared to placebo (Panahi, J Cell Biochem 2019 J).

Be aware that curcumin has a variety of biological effects on the liver -- sometimes beneficial and other times toxic. A review of preclinical research and studies in people concluded that the evidence that curcumin may help to treat people with certain liver diseases is "promising" but limited, and that further studies, particularly long-term studies, are needed (Hu, Ann Hepatol 2017). In addition, some animal studies have found curcumin to help prevent liver damage (Bruck, Liver Int 2007; Chuang, Food Chem Toxicol 2000). Short-term studies in people with moderate daily doses of curcumin (< 500 mg without bioavailability enhancement) have generally not indicated a problem (Kedia, World J Gastrointest Pharmacol Ther 2017; Khajehdehi, J Renal Nutr 2012), but animal studies suggest that high doses of curcumin for a long period of time might be harmful to the liver (Kandarkar, Indian J Exp Biol 1998) and there are cases of liver injury occurring in people taking turmeric/curcumin supplements. There are no long-term safety studies on the effects of curcumin supplementation on liver health.

There has been interest in curcumin to help prevent attacks of gout due to research suggesting that curcumin and its metabolites bind to and may inhibit xanthine oxidase, an enzyme involved in producing urate (uric acid), which can form painful crystals in tissues (Shen, Bioorg Med Chem Lett 2009). Other laboratory research has suggested that curcumin can inhibit a transporter involved in re-absorbing urate from the kidneys, which leads to urate being returned to the blood (Ao, Bioorg Med Chem 2017). However, a study in Thailand among 39 people (average age 55) with persistent hyperuricemia (elevated urate in the blood) found that taking 500 mg of curcumin twice daily for 8 weeks did not reduce blood levels of urate or increase urinary excretion of urate compared to placebo, although both the curcumin and placebo groups showed a reduction in blood levels of urate compared to baseline (-0.6 mg/dL and -0.4 mg/dL, respectively) (Bupparenoo, J Diet Suppl 2021).

Laboratory studies suggest curcumin may inhibit viruses such as influenza, hepatitis C and Zika by interfering with a virus's ability to bind to cells and replicate (Mounce Antiviral Res 2017; Mathew, J Funct Foods 2018). In animal studies, injections of curcumin have been shown to protect the lungs from injury and infection, including viral-induced acute respiratory distress syndrome, possibly by reducing inflammatory cytokines and other mechanisms (Almatroodi, Molecules 2020; Punithavathi, Br J Pharmacol 2000; Avasarala, PLoS One 2013). A small study among 10 children in Italy with recurrent respiratory infections found that a combination of curcumin (100 mg) and lactoferrin (900 mg) taken three times daily for four weeks had a beneficial effect on certain immune system cells (Zuccotti, J Biol Regul Homeost Agents 2009).

A laboratory study that was published online (but not yet in peer-reviewed journal) suggests that curcumin may inhibit the virus that causes COVID-19 (Khaerunnisa, Preprints 2020), and in March 2020 the maker of an intravenous form of liposomal curcumin (Lipocurc, SignPath Pharma) announced that it is "exploring opportunities" to utilize its product in patients with COVID-19. There are no clinical studies to date that have investigated the use of curcumin, in any form, to prevent or treat COVID-19, respiratory infections such as colds or flu, or other viral illnesses.

Curcumin for osteoarthritis in dogs and cats:
A small study in dogs indicated that curcumin (4 mg/kg of body weight) taken twice daily could beneficially affect biochemical pathways associated with decreasing inflammation and pain and improving function in dogs with osteoarthritis; however, due to the size of the study, no conclusions could be drawn (Colitti, Vet Immunol Immunopathol 2012). The curcumin used in the study (Curcuvet, Indena) is a phytosomal formula containing 18-22% curcuminoids made by the makers of Meriva (which is also found in some joint supplements for pets, as well as for people). Curcumin as BCM-95 has been shown to reduce certain markers of chronic low-grade inflammation in obese cats (Leray, Br J Nutr 2011), but there are no studies of its effects in cats with osteoarthritis. Recommended dosing of curcumin for dogs ranges from 50 mg to 250 mg three times daily (depending on the size of the animal) or ½ teaspoon daily of whole turmeric twice daily, and, for cats, 50 mg to 100 mg daily or ¼ teaspoon daily of whole turmeric (Wynn, Veterinary Herbal Medicine 2007).

Be aware that polysorbate 80, which may be included in some curcumin formulations for people (such as Longvida), can cause severe allergic reactions in some dogs (Comblain, J Vet Pharmacol Ther 2016). However, no adverse effects were reported in dogs when black pepper extract, a bioavailability enhancer, was added to a food formulation containing curcumin and other ingredients (Head, J Alzheimers Dis 2012); there do not appear to be such safety studies cats. Unpleasant body odor in dogs taking curcumin has been reported (Dejonckheere, British Association of Veterinary Herbalists 2016). In addition, as with people, turmeric/curcumin should be avoided in dogs and cats taking certain medications or with certain medical conditions (see Concerns and Cautions).

Additional clinical studies of turmeric and curcumin in a variety of diseases are ongoing.

Quality Concerns and Tests Performed:

Like other supplements, neither the FDA nor any other federal or state agency routinely tests turmeric supplements for quality prior to sale. However, quality issues for turmeric supplements can include the following:

· Labeled Amount Does the product really contain the expected amount of turmeric or curcuminoid compounds?

· Purity Does the product contain contaminants? Like other supplements made from plant roots, turmeric may be contaminated with heavy metals, such as lead, cadmium and arsenic -- although such contamination is much more likely to occur in products made from whole turmeric root rather than extracts. It has been reported, for example, that lead chromate, a yellow pigment, is commonly added to poor quality turmeric powder in Bangladesh to enhance its appearance, allowing it to compete with the brighter turmeric from India. Testing of turmeric in Bangladesh revealed that, depending on the region, 11% to 26% of samples exceeded that country's lead limit, while samples from India did not (Forsyth, Environ Res 2019), although turmeric from both countries were recalled across the world between 2011 and 2017 (Cowell, Pub Health Rep 2017). In children, infants, and fetuses, even low levels of lead can adversely affect neurobehavioral development and cognitive function. In adults, lead at somewhat higher levels can cause elevated blood pressure, anemia, and adversely affect the nervous and reproductive systems. Lead is of particular concern during pregnancy as the mother can transfer it to the fetus. Cadmium is a carcinogen and kidney toxin. Arsenic is a carcinogen and can damage organs.

· Ability to Break Apart Properly Once in your body, will the pill break down properly (disintegrate) so that it can release its contents?

ConsumerLab.com, as part of its mission to independently evaluate products that affect health, wellness, and nutrition, purchased many turmeric or curcumin supplements sold in the U.S. and Canada and tested them to determine whether they 1) possessed the claimed and minimum expected amount of curcuminoid compounds, 2) were free of unacceptable levels of lead, cadmium, and arsenic if listing whole turmeric root or over 250 mg of mineral ingredients, and 3) if regular tablets, could disintegrate properly in order to release their contents for absorption (see Testing Methods and Passing Score).

In light of a 2013 FDA report showing 12% of imported spices to be contaminated with filth (e.g. insect parts), ConsumerLab.com also purchased several bottles of ground turmeric root spice, as used in cooking, and tested each for filth, as well as for lead, cadmium and arsenic. (The FDA also reported 7% of imported turmeric spice samples to be contaminated with Salmonella, which led ConsumerLab.com to test turmeric spices for Salmonella in its 2013 review, but Salmonella was not found. Consequently, this test was not repeated in the current Review.)

Interestingly, an analysis by the University of Arizona in Tucson of 87 turmeric/curcumin supplements purchased in early 2017 from local retailers yielded results similar to those found by ConsumerLab over the years: Most products contained the curcumin expected from labels. Heavy metal contamination above 0.5 ppb (0.5 mcg per gram) was noted in only one product -- a turmeric root powder, but not in any extracts. Although traces of solvents (which are used to make extracts) were found in most products, none exceeded USP limits (Skiba, Mol Nutr Food Res 2018). These findings support ConsumerLab's allocation of testing of herbal supplements: All products are tested for key compounds; all herb powders are tested for heavy metals; and solvent testing is generally not performed.

Tests by supplement company, NOW, of 23 competing brands of turmeric/curcumin supplements purchased on Amazon in June 2021 found that one product (Doctor Recommended Turmeric Curcumin) contained only 3% of listed extract, while very low amounts of curcuminoids (8 to 21 mg per capsule) were found in four products (Bioganix, FineVine, NutriFlair, and Pure by Nature), each of which did not clearly state or claim its turmeric/curcumin content. Radiocarbon testing indicated that four products (Vitpro, Me First Living, Eagle, and Primal Harvest) contained "fossil fuel derived organic carbon," possibly indicating synthetic curcumin. Two products (B'Leaf Nature and Eagle) were above California's Prop 65 limits for lead. NOW also found animal gelatin in two products (Bioganix and Nutriflair) labeled as vegetarian capsules. NOW tested two of its own products, with which it reported finding no problems but noted that most of the other products were labeled as "Turmeric Curcumin 1650mg," which could be deceiving, because they were formulas of mostly turmeric powder promising only 50 mg of curcuminoids from turmeric extract.

What CL Found:

ConsumerLab.com's testing showed that supplements provided as much as 1,000 mg or more of curcuminoids per suggested serving or as little as just 10 mg -- as was the case with Member's Mark Turmeric Curcumin, which actually had a lower concentration of curcuminoids than most turmeric spices and was one of only two supplements that we could not approve. Another, Bio Schwartz Turmeric Curcumin With Bioperine, contained just 82.7% of the curcuminoids ConsumerLab expected from its label, with each 3-capsule serving providing 151.3 mg of curcuminoids rather than the expected 183 mg. These results were confirmed in a second, independent laboratory.

A total of 14 supplements were Approved for quality, including five tested through ConsumerLab.com's voluntary Quality Certification Program. Three turmeric spice products were also tested, two of which were Approved for quality, while a third (Simply Organic) could not be approved due to a somewhat low concentration (wt/wt) of curcuminoids (although, it was not the lowest in curcuminoids per teaspoon because its powder was more dense than the others).

None of the products containing turmeric root powder exceeded contamination limits for lead, cadmium or arsenic (products that were only extracts were not tested for heavy metals, since these are largely removed during extraction). All regular tablets broke apart properly to release their ingredients.

Top Picks:

Supplements:
Among the supplements Approved in testing, our Top Pick is Root2 Turmeric Extract Curcumin C3, which provides the highest amount of curcuminoids per daily suggested serving of any product (1,102 mg per day from 2 capsules) at one of the lowest costs (see Cost comparison graph below). Its "C3 Complex" combines turmeric extract with a small amount of black pepper extract (2.3 mg per capsule), that may help with absorption/bioavailability -- but what will probably help more is taking each capsule with a meal containing fats or oils (See "Absorption and Bioavailability"). Doctor's Best High Absorption Curcumin provides a similar amount of C3 for about the same price, but all in one tablet. This is a lot to take at once and, due to curcumin's short half-life, it is better to divide curcumin into two separate doses per day, which is why we prefer the Root2 product.

If for some reason you are not able to take a turmeric supplement with a fat-containing meal, it would be best to use one of the products with enhanced bioavailability. Compared to taking an unformulated curcumin extract with water (from which very little of the curcuminoids will be absorbed), some of these special formulations can increase bioavailability by more than 100 times (for details see "Absorption and Bioavailability"). The formulation that has shown the greatest improvement in bioavailability over straight curcumin is NovaSol, which is found in A1 Vitality Turmeric Curcumin, making it our Top Pick for bioavailability-enhanced curcumin. It is expensive in comparison to other products based on the amount of curcumin it contains, but it should enable you to take a lot less curcumin than with other products. For example, a two-softgel serving (87 cents) of A1 Vitality contains only 60 mg of curcuminoids versus 1,102 mg in a two-capsule serving (47 cents) of Root2, driving up the cost to obtain curcumin and curcuminoids, as shown in the cost comparison graph below. However, taken with just water, it was shown in one study to increase the bioavailability of curcumin 9-fold compared to the C3 formulation in Root2 and by as much as 185-fold compared to plain curcumin.

For pets, we tested one product, Zesty Paws Turmeric Curcumin Bites Joint and Immune System. It contained the expected amount of curcuminoids, with each chew providing 188.7 mg of curcuminoids — which is in line with recommended dosage for dogs, making it our Top Pick for dogs. It includes black pepper extract to increase bioavailability. (Black pepper is not listed as toxic to dogs by the ASPCA or American Veterinary Association, although the long-term safety of black pepper extract has not been evaluated in dogs).

Spices:
ConsumerLab.com purchased three popular ground turmeric spices. McCormick Ground Turmeric is our Top Pick among the spices because it provides a much higher concentration curcuminoids than the other two products, costs less and contains less filth.

As shown in the first graph above, there was a big difference in the amount of curcuminoids among the spices, with McCormick providing 73.4 mg per level teaspoon, which was 63% more than equal amounts of The Spice Hunter and 29% more than Simply Organic.

At $1.63 per teaspoon, McCormick was also slightly lower in cost than The Spice Hunter ($1.68) and much less expensive than Simply Organic ($2.86), as shown in the Cost graph directly above.

In terms of filth, which was measured under a microscope, McCormick also had slightly fewer insect parts (13 fragments) than The Spice Hunter (15 fragments) and far fewer than Simply Organic which contained 25 fragments as well as 3 mites. The higher amount of insect filth in Simply Organic may relate to the fact that it is organic, while pesticides could have been used on the other two products (levels of pesticides were not tested). The presence of insect parts does not pose a health risk, but the FDA sets limits on filth in foods as it represents an aesthetic issue. The limits are known as Defect Action Levels or DALs. A limit has not yet been established by the FDA for turmeric, but the limit for a comparable spice, curry powder, is 100 insect fragments per 25 grams which, for a 10-gram sample (the sample size we used), equates to 40 insect fragments. None of the products exceeded this level.

[Note that, in November 2021, after publication of this review, Consumer Reports published findings of its own tests of turmeric and other spices, focusing on contamination from heavy metals (lead, cadmium, arsenic, and mercury). It did not test The Spice Hunter and, consistent with our findings, it reported "No Concern" with Simply Organic. However, it listed "Some Concern" with McCormick Ground Turmeric.

Consumer Reports did not specify the types or amounts of heavy metals found in products, but posted its test methodology and general ratings criteria. Although we were able to detect heavy metals in McCormick and every spice, none of the amounts exceeded our strict safety limits. In the McCormick product that we tested, we found the following per gram (about 1/5 teaspoon): 0.423 mcg of lead (our limit was 2 mcg/g, which is lower than FDA interim daily limits), 0.119 mcg of cadmium (our limit was 3 mcg for children and 4.1 mcg for adults; there is not FDA limit, but, in Europe it is about 21 mcg for 150 lb person per day), and 0.074 mcg of arsenic (our limit is 10 mcg per daily serving; EPA limits currently under review range from about 7 to 24 mcg for a 150 lb person).

Consumer Reports also reported "Some Concern" with turmeric from Kirkland Signature (Costco), Morton & Bassett, and the highest level of concern with La Flor. It gave a "No Concern" Rating to Laxmi Brand, Spice Islands, Sadaf, Simply Organic, and Badia. Across all spices it reported that roughly one-third "had high enough levels of arsenic, lead, and cadmium combined, on average, to pose a health concern for children when regularly consumed in typical serving sizes. Most raised concern for adults, too."]

Test Results by Product:

Below are two tables. The first displays test results for 16 turmeric or curcumin supplements. Eleven were selected for testing by ConsumerLab.com and five others (each indicated with a CL flask) are included for having passed the same testing through ConsumerLab.com's voluntary Quality Certification Program. Products listed as "Approved" met their label claim and ConsumerLab.com's standards for turmeric supplements. Also shown is the claimed amount and form of turmeric, serving size recommended on the label, total expected amount of curcuminoids per pill, and the cost to obtain 500 mg of curcuminoids. The full list of ingredients is in the last column of the table.

The second table displays test results for three ground turmeric products sold as spices that were selected by ConsumerLab.com for testing. Spices that were "Approved" contained at least 3% curcuminoids (the minimum that is used for turmeric root powder in supplements, but which we applied to the same material in spices). The ingredient description for each spice appears in the second column of the table.

Results of ConsumerLab.com Testing of TURMERIC SUPPLEMENTS

(Click arrows or swipe left or right to see all columns)

Approval Statusⓘ

Product Name

Claimed Turmeric / Curcumin Per Serving

Contained Claimed (C) or Minimum Expected (M)ⓘ, Amount of Curcuminoidsⓘ

Suggested Daily Serving on Label

Pill Sizeⓘ

Cost for Suggested Serving

[Price per 500 mg Curcuminoids]

Price

Notable Features

Full List of Ingredients (Per Serving)

Extract Only:

APPROVED

Top Pick

for bioavailability-enhanced curcumin

A1 Vitality Turmeric Curcumin

Dist. by A1 Vitality

2 softgels
1,000 mg NovaSOL® Curcumin

60 mg curcuminoids (C)
✔

50 mg curcumin (C)
✔

As a food supplement for adults, two (2) softgels daily with an 8oz glass of water, preferably at mealtimes, or as directed by a healthcare practitioner.

Medium/large softgel

$0.87

[$7.22]

$25.99/60 softgels

Free of: Artificial Flavor, Color, Dairy, Gluten, Preservatives, Soy, Sodium, Sugar, Sweetener, Wheat and Yeast.

2 softgels
Calories 10 cal, Total Fat 0 g, NovaSOL® Curcumin (Curcuma Oleoresin of Natural Origin) 1,000 mg, Total NovaSOL® Curcuminoids 60 mg, Total NovaSOL® Curcumin 50 mg.

Ingredients: NovaSOL® Curcumin, more...

APPROVED

Doctor's Best® High Absorption Curcumin

Dist. by Doctor's Best, Inc.

$ Price Check

1 tablet
1,000 mg Curcumin C3 Complex®

750 mg to 810 mg curcumin (C)
✔
Found 858 mg per serving

22 mg to 65 mg bisdemeth-
oxycurcumin (C)
✔
Found 23 mg per serving

150 mg to 190 mg demeth-
oxycurcumin (C)
✔
Found 173 mg per serving

Also tested for disintegrationⓘ
✔

Take 1 tablet daily with food, or as recommended by a nutritionally-informed physician.

Large tablet

$0.42

[$0.20 based on amount found]
Lowest cost for curcuminoids

$50.50/120 tablets

Black pepper extract 5 mg

Suitable for vegans. Non-GMO. Gluten Free. Soy Free.

1 tablet
Curcumin C3 Complex® [Turmeric extract (Curcuma longa) (root), standardized to contain 95% Curcuminoids, including: Bisdemeth-
oxycurcumin (2.2-6.5%), Demeth-
oxycurcumin (15-19%), Curcumin (75-81%)] 1,000 mg, Black Pepper Ext. (Piper nigrum) (fruit) (standardized to contain 95% Piperine) (BioPerine®)] 5 mg.

Other Ingredients: Microcrystalline cellulose, sodium starch glycolate, magnesium stearate (vegetable source), silicon dioxide, hypromellose (coating).

APPROVED

GNC Herbal Plus Turmeric Curcumin 1,000 mg

Dist. by General Nutrition Corporation

1 caplet
1,053 mg turmeric extract

1,000 mg curcuminoids (C)
✔

Also tested for disintegrationⓘ
✔

As a dietary supplement, take one caplet daily.

Large caplet

$0.83

[$0.42]

$49.99/60 caplets

Black pepper fruit extract 20 mg

No Sugar, No Starch, No Artificial Colors, No Artificial Flavors, No Preservatives, Sodium Free, No Wheat, Gluten Free, No Corn, No Soy, No Dairy, Yeast Free.

1 caplet
Turmeric Root Extract (Curcuma longa) (95% Curcuminoids = 1,000 mg) 1,053 mg, Black Pepper Fruit Extract (Piper nigrum) (50% Piperine = 10 mg) 20 mg.

Other Ingredients: Cellulose, Stearic Acid Vegetable Source, Calcium Silicate, Silica, more...

APPROVED

Life Extension® Advanced Bio-Curcumin®

Dist. by Quality Supplements and Vitamins, Inc.

$ Price Check

1 softgel
600 mg turmeric phospholipid blend

380 mg curcuminoids complex
✔
Found 411.7 mg curcuminoids per serving

Take one (1) softgel daily with food, or as recommended by a healthcare practitioner.

Large softgel

$0.68

[$0.82 based on amount found]

$20.25/30 softgels

Gingerols 60 mg

1 softgel
Turmeric Phospholipid Blend [BCM-95® Bio-Curcumin® turmeric 25:1 extract (rhizome) [total curcuminoids complex with essential oils (380 mg)], Turmeric oil (rhizome) [providing 60 mg total turmerones], Phospholipids] 600 mg, Gingerols [from Ginger CO2, extract (root)] 60 mg, more...

APPROVED

Natural Factors® Curcumin Rich® Double Strength Theracurmin®

Mfd. by Natural Factors Canada

$ Price Check

1 vegetarian capsule
60 mg Theracurmin® curcumin extract
✔

Found 63.8 mg curcuminoids per serving

1 capsule per day or as directed by a health professional.

Medium/large vegetarian capsule

$0.64

[$5.02 based on amount found]

$38.47/60 vegetarian capsule

Contains no artificial colors, preservatives, or sweeteners; no dairy, starch, sugar, wheat, gluten, yeast, soy, egg, fish, shellfish, animal products, salt, tree nuts, or GMOs. Suitable for vegetarians/ vegans.

1 vegetarian capsule
Theracurmin® curcumin extract from turmeric (Curcuma longa) (root) [A highly bioavailable form of curcumin - the most active curcuminoid in turmeric] 60 mg.

Other Ingredients: Vegetarian capsule (carbohydrate gum [cellulose], purified water), microcrystalline cellulose, more...

APPROVED

Nordic Naturals® Curcumin Gummies - Mango

Mfd. by Nordic Naturals Mfg.

$ Price Check

2 gummies
200 mg Longvida® Optimized Curcumin extract

36 mg to 44 mg (M) curcuminoidsⓘ
✔
Found 36.7 mg curcuminoids per serving

Two gummies daily, with food, or as directed by your health care professional or pharmacist.

Large cone-shaped gummy

$0.85

[$11.56 based on amount found]

$25.46/60 gummies

Gelatin free. No added sugar. No artificial coloring or flavoring. No gluten, milk derivatives, or artificial colors or flavors.

2 gummies
Calories 15, Total Carbohydrate 5 g, Total Sugars 0 g, Includes 0 g Added Sugars 0 g, Xylitol 3 g, Sodium 30 mg, Longvida® Optimized Curcumin Extract (Curcuma longa root) 200 mg.

Other Ingredients: Prebiotic fiber (from tapioca), pectin, purified water, citric acid, more...

APPROVED

NutriCology® CurcuWIN® 500

Dist. by NutriCology®

$ Price Check

1 vegetarian capsule
500 mg CurcuWIN® turmeric extract

100 mg (C) curcuminoids
✔

As a dietary supplement, 1 capsule one or two times daily with food, or as directed by a healthcare practitioner.

Large vegetarian capsule

$0.50

[$2.49]

$14.95/30 vegetarian capsules

Hypoallergenic.

1 vegetarian capsule
CurcuWIN® Turmeric (Curcuma longa) (Root) Extract (min 20% Curcuminoids) 500 mg.

Other Ingredients: Hydroxypropyl methylcellulose, microcrystalline cellulose, silicon dioxide.

APPROVED

Pure Mark™ Naturals Turmeric Curcumin 95

Mfd. by 21st Century HealthCare, Inc.

1 vegetarian capsule
500 mg turmeric extract

475 mg (C) curcuminoids
✔

As a herbal supplement, adults take one (1) capsule daily with any meal or as directed by a healthcare provider.

Large vegetarian capsule

$0.29

[$0.30]

$17.28/60 vegetarian capsules

Non-GMO. Soy Free. Vegan. Dairy Free. Preservative Free. Gluten & Wheat Free. No Added Sugar, Salt, Yeast, Preservatives, Artificial Flavors or Colors.

1 vegetarian capsule
Turmeric Extract (Curcuma longa) (rhizome) (Standardized to contain 95% Curcuminoids) 500 mg.

Other Ingredients: Cellulose, Rice Hull Concentrate, Magnesium Silicate, Rice Bran Extract. Contains <2% of: Oat Fiber Rice Bran.

APPROVED

Top Pick

Root2 Turmeric Extract Curcumin C3 Complex®

Dist. by Vitacost.com®

2 capsules
1,160 mg turmeric extract

1,102 mg (C) curcuminoids
✔

As a dietary supplement, take 2 capsules daily with food or as directed by a healthcare professional.

Very large capsule

$0.47

[$0.21]

$14.17/60 capsules

Black pepper extract (fruit) 5 mg

Free of: Milk, Eggs, Peanuts, Tree Nuts, Crustacean Shellfish, Fish, Soy, Gluten, Titanium Dioxide.

2 capsules
Turmeric Extract (rhizome) [standardized to 95% curcuminoids (1,102 mg) Curcumin C3 Complex®] 1,160 mg, Black Pepper Extract (fruit) [standardized to 95% piperine (4.75 mg) BioPerine®] 5 mg.

Other Ingredients: Gelatin, Rice Flour, Vegetable Magnesium Stearate, more...

APPROVED

Terry Naturally® CuraMed®

Dist. by EuroPharma, Inc.

$ Price Check

1 softgel
750 mg proprietary complex BCM-95® extract

500 mg (C) curcuminoids
✔

1 softgel daily, may increase as desired.

Large softgel

$0.83

[$0.83]

$49.99/60 softgels

Halal. Non-GMO. No sugar, salt, yeast, wheat, gluten, corn, soy, dairy products, artificial coloring, artificial flavoring, or artificial preservatives.

1 softgel
Proprietary Complex [Curcumin (Curcuma longa) Rhizome Extract (BCM-95®) enhanced with turmeric essential oil and standardized for curcuminoid complex (curcumin, demeth-
oxycurcumin and bisdemeth-
oxycurcumin), phospholipids, supplying 500 mg of pure curcuminoids] 750 mg, more...

APPROVED

Thorne® Meriva 500-SF

Mfd. by Thorne Research, Inc.

$ Price Check

2 capsules
1,000 mg Meriva 500-SF turmeric extract

180 mg to 220 mg (M) curcuminoidsⓘ
✔
Found 190.6 mg curcuminoids per serving

Take 1-2 capsules two times daily or as recommended by your health-care practitioner.

Large capsule

$1.03

[$2.71 based on amount found]

$31.00/60 capsules

Gluten Free. Soy Free.

2 capsules
Curcumin Phytosome (Curcuma longa extract (root) / Phospholipid complex from Sunflower) 1,000 mg.

Other Ingredients: Hypromellose (derived from cellulose) capsule, Leucine, Calcium Laurate, Silicon Dioxide, more...

Root Powder with Extract:

NOT APPROVED

Bio Schwartz™ Turmeric Curcumin With Bioperineⓘ

Dist. by BioSchwartz LLC

3 veggie capsules
1,350 mg turmeric root powder
+
150 mg turmeric extract

40.5 mg (M) (powder) and 142.5 mg (C) (extract)
Found only 151.3 mg curcuminoids per serving (82.7% of expected amount)

Also tested for heavy metalsⓘ
✔

As a dietary supplement, take three (3) capsules, 1 or 2 times per day, preferably with a meal and water or as recommended by a health care professional.

Large veggie cap

$0.63

[$2.08 based on amount found]

$18.87/90 veggie capsules

Black pepper fruit extract 3.3 mg

Free of Soy, Gluten, Milk, Egg, Wheat, GMOs, Peanuts, Sweeteners, Shellfish and Sugar. No Artificial Ingredients, Fillers, Chemicals, Color Additives, Binders or Preservatives.

3 veggie capsules
Turmeric (Curcuma Longa root) 1,350 mg, Turmeric Extract [95% Standardized Curcuminoids] 150 mg, Black Pepper Fruit Extract (BioPerine®) 10 mg.

Other Ingredients: Vegetable capsule (Plantcaps®).

APPROVED

Garden of Life® mykind Organics Extra Strength Turmeric

Dist. by Garden of Life LLC

$ Price Check

1 tablet
553 mg organic turmeric blend

100 mg curcuminoids (C)
✔

Also tested for heavy metalsⓘ
✔

Also tested for disintegrationⓘ
✔

Adults take 1 tablet daily.

Large vegan tablet

$0.35

[$1.75]

$20.99/60 vegan tablets

Organic fermented ginger root 50 mg, organic black pepper fruit extract 7 mg, probiotic blend 4 mg

Kosher. USDA Organic. Non GMO Project Verified. Certified Vegan Vegan.com seal. NSF Certified Gluten-Free seal. Made without dairy or soy ingredients, peanut, tree nuts or shellfish, more...

1 tablet
Organic Turmeric Blend [Organic Turmeric Root Extract standardized to 95% curcuminoids, Organic Fermented Turmeric Root (blend yielding 100 mg curcuminoids)] 553 mg, Organic Fermented Ginger Root 50 mg, Organic Black Pepper Fruit Extract 7 mg, more...

NAⓘ

Member's Mark® [Sam's Club] Turmeric Curcumin Complex

Dist. by Sam's West, Inc.

1 capsule
500 mg Biocumin™ turmeric/curcumin complex

Found 9.7 mg curcuminoids per serving
Very low amount.
Suggests that only 1.9% of Biocumin™ complex is curcuminoids, even less than in regular root powder.

Also tested for heavy metalsⓘ
✔

Adults - One capsule daily with food as a dietary supplement.

Large capsule

$0.06

[$3.06 based on amount found]

$14.88/250 capsules

Suitable for vegetarians. No Artificial Colors Or Flavors. No Sugar. No Gluten. No Lactose. No Trans Fat.

Precaution: Contains: Soy.

1 capsule
Sodium 10 mg, Total Carbohydrate <1 g, Biocumin™ Turmeric / Curcumin Complex [Turmeric (Curcuma longa) Root Powder, 95% Standardized Turmeric (Curcuma longa) Extract, Antioxidants (ascorbic acid [Vitamin C] and d-alpha tocopheryl succinate [Vitamin E]) 500 mg, more...

APPROVED

Nature's Bounty Turmeric 450 mg

Mfd. by Nature's Bounty, Inc.

$ Price Check

1 capsule
450 mg turmeric root powder
+
50 mg turmeric extract

13.5 mg (M) (powder) and 47.5 mg (C) (extract)
✔
Found 60.3 mg curcuminoids per serving

Also tested for heavy metalsⓘ
✔

For adults, take one (1) capsule daily, preferably with a meal.

Large capsule

$0.13

[$1.09 based on amount found]

$7.90/60 capsules

Non-GMO, No Artificial Color, No Artificial Flavor, No Artificial Sweetener, No Preservatives, No Sugar, No Starch, No Milk, No Lactose, No Soy, No Gluten, No Wheat, No Yeast, No Fish, Sodium Free.

1 capsule
Turmeric (Curcuma Longa) (root) 450 mg, Turmeric Extract (Curcuma longa) (root) (Standardized to contain 95% Curcuminoids) 50 mg.

Other Ingredients: Gelatin. Contains <2% of: Silica, Vegetable Magnesium Stearate, Vegetable Stearic Acid.

Pet Products:

APPROVED

Top Pick

for Dogs

Zesty Paws® Turmeric Curcumin Bites™ⓘ

Dist. by Zenwise Health LLC

$ Price Check

1 soft chew
400 mg organic turmeric
+
200 mg Qmin+™ turmeric extract

12 mg (M) (powder) and 190 mg (C) curcuminoids
✔
Found 188.7 mg curcuminoids per serving

Also tested for heavy metalsⓘ
✔

Up To 25 lbs: 1 Soft Chew; 26 - 75 lbs: 2 Soft Chews; Over 75 lbs: 3 Soft Chews.

Large heart-shaped soft chew

$0.29-$0.87

[$0.76 based on amount found]

$25.97/90 soft chews

BioPerine® 5 mg

No Ingredients Derived From: Grain, Corn, Soy. No Artificial Flavoring. No Artificial Preservatives.

1 soft chew
Calories (kcal) 22, Total Fat 1.5 g, Coconut Oil 420 mg, Organic Turmeric 400 mg, Qmin+™ Curcumin (Curcuma longa) Rhizome Extract (Minimum 95% Curcuminoids) 200 mg, BioPerine® (Piper nigrum, Fruit) (Standardized to Minimum 95% Piperine) 5 mg, more...

Unless otherwise noted, information about the products listed above is based on the samples purchased by ConsumerLab.com (CL) for this Product Review. Manufacturers may change ingredients and label information at any time, so be sure to check labels carefully when evaluating the products you use or buy. If a product's ingredients differ from what is listed above, it may not necessarily be of the same quality as what was tested.

The information contained in this report is based on the compilation and review of information from product labeling and analytic testing. CL applies what it believes to be the most appropriate testing methods and standards. The information in this report does not reflect the opinion or recommendation of CL, its officers or employees. CL cannot assure the accuracy of information.

Copyright ConsumerLab.com, LLC, 2021 All rights reserved. Not to be reproduced, excerpted, or cited in any fashion without the express written permission of ConsumerLab.com LLC

Results of ConsumerLab.com Testing of TURMERIC SPICES

(Click arrows or swipe left or right to see all columns)

Approval Statusⓘ

Product Name

Type of Turmeric

Amount of Curcuminoids Found Per Gramⓘ and Per Level Teaspoon

Did Not Exceed Contamination Limit for Lead, Cadmium and Arsenicⓘ

Filth: Insect Fragments & Other Adulterants (Per 10 Grams)ⓘ

Notable Features

Cost Per Ounce of Ground Turmeric

[Price Per 500 mg Curcuminoids Found]

Price Paid

APPROVED

Top Pick

McCormick Ground Turmeric

Dist. by McCormick & Co., Inc.

Ground

Found:
73.4 mg/tsp
41.1 mg/gram
(4.1% wt/wt)
✔

✔

13 fragments

Kosher. Non-GMO.

$3.67

[$1.63]
Lowest cost for curcuminoids from spice

$3.49/0.95 oz [26 g] jar

NAⓘ

Simply Organic® Turmeric

Dist. by Frontier Co-Op

$ Price Check

Ground, Organic

Found:
56.8 mg/tsp
22 mg/gram
(2.2% wt/wt)

✔

24 fragments

3 mites

Kosher. Quality Assurance International Certified Organic Seal. USDA Organic seal.

$3.57

[$2.86]

$1.89/0.53 oz [15 g] jar

APPROVED

The Spice Hunter® India Turmeric Gourmet

Dist. by The Spice Hunter, Inc.

Ground, Gourmet (from India)

Found:
44.9 mg/tsp
29.2 mg/gram
(2.9% wt/wt)
✔

✔

15 fragments

Kosher. Non GMO Project Verified seal.

$2.75

[$1.68]

$5.50/2 oz [56 g] jar

Unless otherwise noted, information about the products listed above is based on the samples purchased by ConsumerLab.com (CL) for this Product Review. Manufacturers may change ingredients and label information at any time, so be sure to check labels carefully when evaluating the products you use or buy. If a product's ingredients differ from what is listed above, it may not necessarily be of the same quality as what was tested.

The information contained in this report is based on the compilation and review of information from product labeling and analytic testing. CL applies what it believes to be the most appropriate testing methods and standards. The information in this report does not reflect the opinion or recommendation of CL, its officers or employees. CL cannot assure the accuracy of information.

Copyright ConsumerLab.com, LLC, 2021 All rights reserved. Not to be reproduced, excerpted, or cited in any fashion without the express written permission of ConsumerLab.com LLC

ConsumerTips™:

Consumers should look for the following information on turmeric supplement labels:

· Species of turmeric (look for Curcuma longa, although the use of the accepted common name "turmeric" is sufficient to denote this species)

· Part of the plant used (should be "root" or "rhizome")

· Form of turmeric used (e.g., root/rhizome powder or extract)

· Amount of turmeric per pill or dose in grams (g) or milligrams (mg) [1 gram = 1,000 milligrams]

All of the above information is required by the FDA to appear on labels. While it is preferable that the concentration of curcumin also be indicated, optimal doses of curcumin have not yet been established.

You may notice slight variation in the orange-yellow color of curcumin or turmeric from product-to-product and even from lot-to-lot for a specific product. This is not necessarily a problem. What is most important is whether or not the product provides the correct amount of curcuminoid compounds (as discussed above in "What CL Found"). Reasons for color variation include how the root powder or extract is prepared (even roots used to make root powders are typically briefly boiled to help "set" the turmeric), seasonal and climatic variations in the regions from which the root is sourced, and a change in the ingredient supplier used by a manufacturer.

Clinical studies with turmeric root powder have generally used 3 to 12 grams (3,000 mg to 12,000 mg) daily. However, the bulky volume of more than 8 grams per day may be unacceptable to some people. Appropriate doses depend on the form and concentration of turmeric used in the supplement.

The best way to take curcumin and turmeric supplements:
The best way to take a curcumin or turmeric supplement is to take it twice a day because it has a half-life of just a couple of hours and, each time, to take it with a meal that contains some fat or oil. The reason to take it with a fat-containing meal is that (as discussed in the Absorption and Bioavailability section below) standard curcumin has low bioavailability and only a small percentage of the curcumin (if not bioavailability enhanced) will be absorbed. Most clinical studies of curcumin and turmeric use twice-daily dosing.

Even products that contain bioavailability-enhanced formulations of curcumin are probably best taken twice daily and with a fatty meal to further boost absorption.

Be aware that you'll absorb little curcumin if adding turmeric or curcumin to tea or to a fruit or vegetable smoothy containing little fat. Adding whole or reduced-fat milk or yogurt, or vegetable/seed oils, will provide fats that can enhance curcumin absorption. Cooking with turmeric:
Diets high in the spice turmeric will contain about 60 to 100 mg of curcumin per day, although doses used therapeutically are typically several times higher than this. If you are cooking with turmeric spice, be aware that some curcumin may be lost due to heat or chemical changes during cooking. An experiment in which 1 gram of turmeric (providing 33 mg of curcumin) was added to bread, an oat bar, or soup prior to baking or cooking found that each contained, respectively, just 52%, 48%, or 71% of the original curcumin after being made (Mahale, Mol Nutr Food Res 2018). (Note: Adding black pepper to turmeric-containing foods can increase the bioavailability of the curcumin and, as noted earlier, consuming such foods with as part of a fat-containing meal will help to increase curcumin absorption.)

Turmeric powder vs. freshly grated turmeric
A small study found that, when mixed into a high-fat meal (mashed potatoes with cream providing 40 grams of fat), the curcuminoids in turmeric powder (12 grams) were about twice as bioavailable as those from freshly grated turmeric (83 grams). Interestingly, both forms of turmeric raised levels of curcuminoids in the blood far more than curcumin powder (500 mg -- 95% curcuminoids) mixed into the same meal, despite all three products containing the same amount of curcumin. The researchers speculated that compounds naturally in turmeric but not in curcumin powder, such as oils or starches, naturally enhance the absorption of curcuminoids (Nasef, Food Funct 2019).

Dosage used

· To treat dyspepsia, one study used 500 mg turmeric powder four times daily (2 grams per day of turmeric) for seven days (Thamlikitkul, J Med Assoc Thai 1989).

· For ulcerative colitis, 1.5 grams of curcumin was used twice a day (3 grams per day of curcumin) to attain remission in patients with active mild to moderate ulcerative colitis (Lang, Clin Gatroenterol Hepatol 2015). One gram of curcumin was used twice a day to maintain remission (2 grams per day of curcumin) (Hanai, Clin Gastroenterol Hepatol 2006).

· For ulcerative proctitis 550 mg of curcumin was used twice daily for 1 month and then 550 mg three times daily for another month (Holt, Digestive Diseases and Sciences 2005).

· For chronic anterior uveitis, 375 mg of curcumin three times a day (1.1 grams per day of curcumin) was used in a three-month study (Lal, Phytother Res 1999).

· For rheumatoid arthritis, 1,200 mg per day (Deodhar, Indian J Med Res, 1980) or 500 mg twice daily of a specific curcumin product (BCM-95, Biocurcumin) (Chandran, Phytother Res 2012).

· For osteoarthritis of the knee, 1,500 mg daily of curcuminoids taken for six weeks as a capsule with 500 mg of curcuminoids as C3 complex® including 5 mg of Bioperine® three times a day (Panahi, Phytother Res 2014). Also as three capsules daily of 500 mg of BCM-95 (each providing 333 mg of curcuminoids) (Haroyan, BMC Compl Alt Med 2018).

· For seasonal allergy, 500 mg of curcumin daily for 8 weeks (Wu, Ann Allergy Asthma Immunol 2016).

· For reducing delayed-onset muscle soreness after exercise, 200 mg of curcumin (from 1 gram of Meriva®) at breakfast and dinner for two days prior to exercise and the day of exercise, and one day after exercise (Drobnic, JISSN 2014).

· For treating psoriasis, a curcuminoid C3 complex containing 95% curcuminoids has been given as three 500 mg capsules three times daily (4.5 grams per day) (Kurd, J Am Acad Dermatol, 2008).

· For preventing early changes in the colon that might lead to colon cancer, 4 grams of micronized 98% curcumin daily reduced the number of crypt foci in a one-month study in smokers. A 2-gram dose was not effective. (Carroll, Cancer Prev Res Phila 2011).

· For treating pancreatic cancer, 8 grams of curcumin have been given daily (Dhillon, Clin Cancer Res 2008).

· For preventing the progression of prediabetes to diabetes, 1.5 grams of curcuminoids in two divided doses has been given daily in a 9-month study (Chuengsamarn, Diabetes Care 2012).

· For improving symptoms of major depression, curcumin (500 mg of BCM-95) twice daily may reduce depressive symptoms, particularly among individuals with atypical depression (Lopresti, J Affect Disorders 2014).

· For improving short-term memory, 1 gram of turmeric powder taken with breakfast (Lee, Asia Pac J Nutr 2014). Also, to improve some aspects of cognitive function and fatigue, 400 mg after breakfast of a patented curcumin formula containing 80 mg curcumin plus fats to enhance absorption (Longvida® Optimized Curcumin) (Cox, J Psychopharm 2014).

Some products contain a patented Curcumin C3 Complex which, according to its manufacturer, Sabinsa Corporation, is standardized to 95% curcuminoids. In this Review, it is used in Doctor's Best High Absorption Curcumin and Root2 Turmeric Extract Curcumin C3 Complex.

Based on ConsumerLab.com's analyses of the products in this report, curcumin accounted for approximately 70% of total curcuminoids in concentrated extracts (such as those standardized to 95% curcuminoids) and approximately 56% of total curcuminoids in products made from only root powder.

Absorption and Bioavailability
If taken with only with water, only a limited percentage of curcumin taken orally will be absorbed into the blood because much of what is ingested is metabolized in the intestine and/or excreted in the stool. In addition, unformulated curcumin has a short half-life (the amount of time it takes for blood levels to fall by half) of two hours or less (Suresh, CrystEngComm 2018). As curcumin is lipophilic (it binds to fats), taking curcumin with foods containing fats or oils will enhance absorption as they stimulate the product of bile, which, in turn, aids the absorption of fats and lipophilic compounds like curcumin.

Bioavailability-Enhanced Formulations
Due to its poor natural bioavailability, a variety of special formulations have been developed to improve the absorption, half-life, and bioavailability of curcumin when taken with only water. Any product labeled as containing one of these formulations is specially marked in the second column of the Results table above.

Many small studies have compared the bioavailability of these special formulations to determine how much curcumin, or it and its metabolites (total curcuminoids), make it into the blood over time. Due to differences in how the studies were conducted, it is difficult to compare results across studies. However, a common finding in these studies is that the formulation with the greatest bioavailability for both curcumin and/or total curcuminoids has tended to be NovaSol.

An independent analysis in 2018 of bioavailability studies that had been conducted (the majority of which appeared to involve developers or manufacturers of the studied formulations) concluded that, compared to the bioavailability of unformulated curcumin, NovaSol had the highest bioavailability (185 X that of unformulated curcumin), followed by Curcuwin (136 X), Longvida (100 X), Meriva (48 X), BCM-95 (27 X), Curcumin C3 Complex+Bioperine (20 X), and then Theracurmin (16 X), based, apparently, on measurements of curcumin in the blood (Jamwal, J Integr Med 2018).

A subsequent clinical study in which a small number of men and women were given each of several formulations over time (taken with only water and on an empty stomach) found that the formulations that most increased curcumin bioavailability were those that increased the water solubility of curcumin as well as its incorporation into micelles (tiny fat droplets absorbed through the intestine). Two formulations that were shown to do this were micellar curcumin (NovaSOL) and gamma-cyclodextrin curcumin (Cavacurmin), which respectively, had 57-fold and 30-fold greater bioavailability of curcumin compared to unformulated curcumin. Both of these formulations also improved curcumin stability during simulated gastric and intestinal digestion. On the other hand, formulations that prevented the metabolism of curcumin (i.e., one with piperine) and those that increased curcumin solubility in water but not its stability during digestion or its incorporation into micelles (including BCM-95, Longvida, Meriva and Theracurmin) did not significantly improve curcumin bioavailability compared to unformulated curcumin (Flory, Mol Nutr Food Res 2021).

Another comparison study of special formulations — all taken only with 8 oz. of water on an empty stomach — also found that NovaSOL had the highest bioavailability for total curcuminoids, followed by Turmipure GOLD (from Naturex), Naturex standard extract, C3 Complex, and finally, Meriva. However, when looking specifically at the bioavailability of only curcumin, the main curcuminoid compound, there were no significant differences between formulations. The study was funded by Naturex (Fanca-Berthon, J Nutr 2021). Turmipure GOLD is a dried colloidal suspension of standard turmeric extract, quillaja extract, sunflower oil, and acacia gum (1,500 mg total standardized to 30% curcumin, providing 90 mg of curcuminoids) and is sold as a powder to be mixed with water. It is not an ingredient in any of the products tested in this review, but is marketed in the U.S. by Wellness Resources.

Keep in mind that none of the comparison studies above involved taking supplements along with a high-fat meal — had they, it's possible that absorption rates across formulations would be more similar to one another as well as to unformulated curcumin. If you don't plan on taking your turmeric/curcumin supplement with a meal, it's probably worth taking a product formulated to enhance absorption, as you will, otherwise, naturally absorb only a small amount of curcuminoids.

More information about some of these formulations follows (listed alphabetically) follows. (See the What It Does section for information about how these have been used for specific therapeutic uses):

BCM-95 reconstitutes curcuminoids with other components of turmeric such as turmeric oils. A small study showed the bioavailability of BCM-95 to be about 7 times that of normal curcumin, and about 6 times that of a curcumin-lecithin-piperine complex (Antony, Indian J Pharma Sciences 2008). BCM-95 is found in products such as Terry Naturally CuraMed (tested in this Review) and others such as Curcumin Extreme and Life Extension Super Bio-Curcumin. BCM-95 is manufactured by Arjurna Natural Extracts, Inc. and distributed by DolCas Biotech in the U.S.

Bioperine® (Sabinsa Corporation) is a patented black pepper extract containing the compound piperine, which inhibits the metabolism of curcumin in the gut and liver (Shoba, Planta Med 1998). The piperine in Bioperine is claimed to have increased the bioavailability of curcumin by 20 times in people (based on giving 20 mg of piperine with a 2,000 mg dose of curcumin) and by 154% in rats — although both these figures are based on studies in which plain curcumin was given with just water, so hardly any was absorbed, making the comparisons fairly meaningless. Bioperine is part of the C³ complex in the Doctor's Best High Absorption Curcumin and Root2 Turmeric Extract Curcumin C3 Complex, tested and Approved in this Review. You can also get a significant amount of piperine from regular ground black pepper — just 1/4 teaspoon of ground pepper (about 500 mg) should provide 10 to 35 mg of piperine, because black pepper is 2-7% piperine (Gorgani, Compr Rev Food Sci Food Saf 2016). In contrast, only about 2.5 to 5 mg of piperine is typically added to curcumin supplements — which normally contain a lot more curcumin than in foods spiced with turmeric.

Be aware that piperine may also significantly increase the absorption of other compounds, including certain medications (See Cautions and Concerns). Black pepper extract and piperine are reported to have diuretic properties (increasing urine output) and stimulate the production of stomach acid (Meghwal, Scientific Reports 2012). One animal study found lower doses of both black pepper extract and piperine to have a laxative effect, while higher doses were found to slow intestinal motility and have an antidiarrheal effect — although in these studies both doses were significantly higher than amounts found in curcumin supplements (Mehmood, J Med Food 2010). In people, there do not appear to be any reported adverse effects when taken at typical doses; Bioperine® is self-affirmed GRAS (generally recognized as safe) (FDA 2013).

Curcugen (Olene Life Sciences Pvt. Ltd.) is a standardized curcumin formulation described as "98.5% turmeric-dervived" -- of which 50% is curcuminoids, and 1.5% is turmeric essential oils and turmeric polysaccharides, which are intended to improve dispersion and increase bioavailability. In a small company-funded study among healthy young men, Curcugen was found to be 31 times as bioavailable as a curcumin extract standardized to 95% curcuminoids, when each was taken on an empty stomach (Panda, Medicine (Baltimore) 2021). Curcugen is sold as an ingredient in Wellness 26 CurcuOne with Curcugen.

CurcuWin (OmniActive Health Technologies) combines curcumin with a hydrophilic carrier, making it more dispersible in water. A study funded by OmniActive found that CurcuWin increased curcuminoid levels in the blood plasma 4,490% above that achieved with standard curcumin and was estimated to have a half-life of six to seven hours (Jager, Nutr J 2014). The study also evaluated BCM-95 and Meriva, finding them, respectively, to increase total curcuminoid blood levels 30% and 690% above that with standard curcumin. In the study, the supplements were taken with water on an empty stomach, putting standard curcumin at a great disadvantage since its absorption is enhanced when taken with a fatty (oily) meal. CurcuWin is 20% curcuminoids, i.e., 250 mg of CurcuWin contains 50 mg of curcuminoids. CurcuWin is found in one product in this review: Member's Mark Turmeric Curcumin Complex.

Meriva (Indena S.p.A.) is a proprietary phytosomal combination of phosphatidylcholine-enriched soy lecithin and curcumin. (Phytosome enhancers combine supplement ingredients with phosphatidylcholine, a natural surfactant that dissolves in both water and oil.) A study in rats showed a 5-fold increase in bioavailability with Meriva compared to curcumin and even greater increases in other curcuminoids (Marczylo, Cancer Chemother Pharmacol 2007). A study in humans (Cuomo, J Nat Prod 2011) also suggested increased absorption from Meriva. The small study showed a significant increase in plasma levels of curcumin metabolites -- although not of curcumin itself - from capsules of Meriva compared to capsules containing unformulated curcuminoids. Both were taken with a snack providing some fat (a bagel with cream cheese). Overall, curcuminoid absorption from Meriva was 29-fold higher than from the unformulated product. Meriva is a "complex" of which 18% is curcuminoids, i.e., 1,000 mg of Meriva contains 180 mg of curcuminoids. One product in this review, Thorne Meriva 500-SF, contains Meriva.

NovaSol (Molecular Health Technologies) combines micronized curcumin (7% of the formula) with the surfactant polysorbate 80 (93% of the formula), which leads to the formation of micelles (similar to the effect of bile) that improve dissolution and absorption. A study (co-authored by developers of NovaSol) in adults found this to increase bioavailability 185-fold higher than unformulated curcumin, with both taken in the morning after a 12-hour fast (Schiborr, Mol Nutr Res 2014). NovaSol is an ingredient in A1 Vitality Turmeric Curcumin, which was tested and Approved in this review.

Theracurmin (Theravalues Corp.) is a "nanoparticle" formulation in which the size of curcumin particles is greatly reduced and microencapsulated with an emulsifying agent (gum ghatti) making the curcumin more dispersible in water. A study funded by Theravalues showed that Theracurmin raised blood levels of curcumin 27 times as much as taking an equivalent amount of regular curcumin powder (Sasaki, Biol Pharm Bull 2011). However, it is important to note that both forms of curcumin were taken with 100 mL of mineral water, and not food, putting regular curcumin at a disadvantage since fats can enhance the absorption of standard curcumin. Another study funded by Theravalues found that taking Theracurmin lead to levels of curcumin in the blood (over 24 hours) that were about 4 times that of Meriva and at least 11 times that of BCM-95. Again, all were taken with just a sip of water and on an empty stomach (Sunagawa, J Nutr Sci Vitaminol 2014). Based on a small study in people, Theracurmin is estimated to have a half-life of about 9 to 13 hours (Kanai, Cancer Chemother Pharmacol 2012). Theracurmin is 30% curcumin, i.e., 60 mg of Theracurmin contains 18 mg of curcumin. In this review, this formulation can be found in Natural Factors Curcumin Rich Double Strength Theracurmin. (See What It Does for more about Theracurmin).

Concerns and Cautions:

Turmeric products are believed to be safe for short periods of time at doses as high as eight grams (8,000 mg) per day of curcumin, although they can cause side effects including headache, nausea, diarrhea, yellow stool, allergic skin reactions, and increases in serum alkaline phosphatase and lactate dehydrogenase (Burgos-Moron, Int J Cancer 2010; Lao, BMC Complement Altern Med 2006). A study in 21 people with advanced stage pancreatic cancer, found that eight grams of curcuminoids taken daily for up to 18 months did not cause toxic effects (Dhillon, Clin Cancer Res 2008), although formal, long-term safety studies have not been conducted. Formulas with enhanced bioavailability could be more potent: the longest clinical study with such a product involved giving 1 gram (1,000 mg) of Meriva (providing 200 mg of curcuminoids), taken in divided doses after breakfast and dinner, which was safely taken for eight months (Belcaro, Alt Med Rev 2010).

· Turmeric can stimulate the gallbladder, causing greater contractions (Rasyid, Asia Pac J Clin Nutr 2002) and could, therefore, increase pain during stone passage in people with gallstones or in people with gallbladder disease, although it does not contribute to the formation of gallstones or gallbladder disease.

· Use of turmeric/curcumin for a month or longer may adversely affect the liver in a small percentage of people, and there has been a steady stream of such reports, mainly from the U.S. Most cases have been in women. Here are recent reports -- take note of the symptoms:

· A 55-year-old woman in the U.S. with Hashimoto's disease (an autoimmune disease of the thyroid) developed autoimmune hepatitis with symptoms including nausea, vomiting, dark urine, and jaundice after taking a turmeric supplement (Qunol Liquid Turmeric -- 15 mL per day) for three months. She was evaluated at a liver clinic and underwent a liver biopsy to rule out other causes. Within one month of stopping the supplement, her symptoms resolved and levels of bilirubin and liver enzymes decreased to mostly within normal range after one month of stopping supplementation (Lee, ACG Case Rep J 2020).

· A 52-year old Caucasian woman in Australia developed acute, severe hepatitis one month after she began taking a daily tablet providing 375 mg of curcuminoids and 4 mg black pepper per tablet (which was not found to be adulterated or contaminated). Her symptoms included nausea, itching, painless jaundice, pale stools and dark urine. Her liver function tests normalized two months after stopping turmeric and an anti-inflammatory drug, but she then resumed only the turmeric (for her osteoarthritis) and, three weeks later, nausea returned along with elevated liver enzymes. Her condition resolved two months after discontinuing the turmeric (Luber, Case Rep Hep, 2019).

· A 51-year old woman who regularly took a daily multivitamin, primrose oil and an omega-3 fatty acid supplement, and occasionally used acetaminophen, developed elevated liver enzymes and symptoms including fatigue, lack of appetite, abdominal pain and dark urine two months after beginning daily supplementation with a turmeric supplement (containing 400 mg of turmeric powder, 50 mg of turmeric extract, and 50 mg of ginger powder). After receiving treatment and stopping turmeric supplementation, her liver enzymes decreased to less than 50% within 6 days and returned to normal limits in 8 weeks (Abdallah, Am J Ther 2019).

· A 61-year old women with polycystic liver disease developed similar liver dysfunction and symptoms, as well as joint pain, after taking turmeric supplements (details not provided) for six months (in addition to taking vitamin D and naproxen without problem for four years). Symptoms resolved three weeks after treatment with prednisone and stopping supplementation (Suhail, Clin Toxicol 2019).

· A 78-year-old woman with well-controlled type 2 diabetes and high blood pressure who took a daily curcumin supplement (providing 500 mg of curcumin) for one month developed elevated liver enzymes (ALP, AST and ALT), jaundice, and pale stools. Seven days after supplementation was stopped, there was a >40% improvement in ALT and AST levels; jaundice completely resolved after 42 days, and liver enzymes levels returned to normal within two months of stopping supplementation (Imam, Case Rep Gastrointest Med 2019).

· For example, a 71-year-old woman was found to have elevated liver enzymes (AST and ALT) due to drug-induced autoimmune hepatitis after taking a turmeric supplement for 8 to 12 months. Her liver enzyme levels decreased within one month of stopping turmeric supplementation and normalized within one year. The doctors who reported the case reviewed 20 turmeric/curcumin clinical trials in which liver function was monitored and found a 5% overall incidence of abnormal liver function when supplementation lasted for longer than one month (Lukfahr, BMJ Case Rep 2018).

· Some animal studies have also found possible toxicity to the liver when large doses are given for prolonged periods of time (Kandarkar, Indian J Exp Biol 1998); although other animal studies have found curcumin to help prevent liver damage (Bruck, Liver Int 2007; Chuang, Food Chem Toxicol 2000).

· Turmeric contains a substantial amount of oxalate, a substance that can bind with calcium to form calcium oxalate kidney stones (the most common type of kidney stone). Individuals who are prone to developing these stones may want to limit oxalate intake (American Urological Association 2017). Some low-oxalate diets advise getting no more than 50 — 100 mg of oxalate per day. An analysis of one particular turmeric powder (Puritan's Pride) found it to contain 20 mg of oxalate per gram, and a daily dose of 2.8 grams of this turmeric powder (containing approximately 55 mg of total oxalate) taken daily for 4 weeks was found to significantly increase urinary oxalate levels (Tang, Am J Clin Nutr 2008). However, certain curcumin formulas claim to contain little or no oxalate: Curcumin C3 Complex (found in Doctor's Best and Root2 Turmeric Extract Curcumin C3 Complex in this Review) claims just 0.025 mg of oxalate per 500 mg dose, and BCM-95 (Biocurmin) (found in Terry Naturals in this Review) claims to be free of oxalates. Be aware that some products containing these branded ingredients may contain additional forms of turmeric/curcumin or other ingredients that have not been analyzed for oxalate content.

· Turmeric has anti-platelet activity. Avoid using turmeric while taking blood-thinners -- anticoagulant/antiplatelet drugs such aspirin, clopidogrel (Plavix), warfarin (Coumadin), rivaroxaban (Xarelto) (Shah Biochem Pharmacol 1999).

· Although some research indicates that curcumin may lower blood sugar levels and reduce the chance of prediabetes progressing to diabetes (See What It Does), this also means that it may interact with blood sugar lowering medication. For example, taking 475 mg daily of curcumin was shown to enhance the blood-sugar lowering effect of glyburide in people with type-2 diabetes (Neerati, Phyto Res 2014). People with hypoglycemia or those taking medication to lower blood sugar, including insulin, glyburide (DiaBeta, Micronase, Glynase) pioglitazone (Actos), and rosiglitazone (Avandia) should use with curcumin caution.

· There is some evidence that curcumin may decrease the bioavailability of the beta-blocker drug talinolol (Juan, Eur J Clin Pharmacol 2007).

· Some laboratory studies suggest that curcumin in turmeric may interfere with the cytochrome P450 3A (CYP3A4) subfamily of enzymes that normally metabolize tacrolimus and other drugs and, therefore, increase blood levels of certain drugs (Kocher, Ernahrungs Umschau 2015). This occurred in the case of 56-year-old man in the U.S. taking tacrolimus (FK-506, Protopic, Prograf, Hecoria), an immunosuppressant drug taken after organ transplantation. After liver transplantation the man reported adding large amounts of turmeric to his food (estimated at 15+ spoonfuls daily — which would equal about 75 grams and provide approximately 2,250 mg of curcuminoids) for at least ten days; he was hospitalized for dangerously elevated blood levels of the drug, and evidence of kidney damage (worsening edema and an elevated blood creatinine level) which improved four days after eliminating turmeric intake and temporarily withholding tacrolimus (Nayeri, Transplant Proc 2017). This is the first reported case suggesting this interaction in humans. Other drugs that are metabolized by this enzyme and could theoretically be affected this way (although there are no reported cases) include midazolam (Versed), cisapride (Propulsid), fentanyl (Sublimaze), lidocaine (Xylocaine), losartan (Cozaar), fexofenadine (Allegra) omeprazole (Prilosec), ondansetron (Zofran), the blood pressure lowering drugs felodipine (Plendil) and amlodipine (Norvasc), the antibiotic rifampin, and certain calcium channel blockers (diltiazem, nicardipine, verapamil). However, there do not appear to be studies on the effects of curcumin on these drugs in people.

· Preliminary research suggests that taking curcumin could potentially increase the effects of the anti-inflammatory drug sulfasalazine (Azulfidine) (Kushuhara, B J Pharmacol 2012).

· Curcumin may also decrease levels of certain drugs. Laboratory research has also shown that metabolites of curcumin, which occur at high levels in the blood, can activate CYP3A4 and therefore, decrease levels of drugs. Two cases have been reported in which curcumin (at <doses of 400 mg per day and 12 mg with 0.3 mg of piperine per day) appeared to significantly decrease blood levels of the immunosuppressant/anti-cancer drug everolimus. Blood concentration of the drug rose back to expected levels upon discontinuation of curcumin (Mir, Ann Oncol 2017). A study of 16 women with breast cancer being treated with tamoxifen found that high doses of curcumin (1,200 mg curcumin per dose taken 3 times per day) decreased the absorption of tamoxifen (20 - 30 mg dose) taken the same day by 8%, and by 12.8% if the curcumin included 10 mg per dose of piperine, and significantly decreased blood levels of the drug's main metabolite (endoxifen) compared to taking tamoxifen alone. Taking curcumin with tamoxifen could decrease concentrations of endoxifen below the threshold for efficacy for potentially 20 - 40% of patients, especially those with certain CYP2D6 genetic variations (Hussaarts, Cancers 2019).

· Laboratory and animal studies suggest that curcumin can bind to and reduce the availability of iron and may lower iron levels in the body (Tuntipopipat, Int J Food Sci Nutr 2009; Jiao, Blood 2009). A 66-year-old man, for example, developed iron deficiency anemia three months after beginning high-dose supplementation with turmeric (six 538-mg turmeric extract capsules a day), even though he was also taking a daily iron supplement (28 mg of elemental iron twice a day). Within two weeks of discontinuing the turmeric extract, while continuing the iron supplement, his hemoglobin levels returned to normal and his blood iron level began to increase (Smith, Cureus 2019). It would seem prudent for people who are anemic or with marginal iron stores to avoid taking curcumin supplements or to use them at least two to three hours apart from consuming iron-containing meals or supplements. A small study in healthy women without iron deficiency found that 500 mg of ground turmeric added to an iron fortified meal did not inhibit iron absorption (Tuntipopipat, J Clin Nutr 2006). However, this amount of turmeric would provide only a small amount of curcuminoids (as little as 15 mg), in contrast to the hundreds of milligrams of curcuminoid compounds in a standard dose of curcumin (turmeric extract).

· Curcumin can act as a MAO inhibitor, but this has only be demonstrated in animals when given intravenously at high doses (Kulkarni, Pyschopharmacology 2008). There are no studies on curcumin's effect on MAO inhibition in people taking oral supplements, which have significantly lower absorption and tend to be taken in much lower doses.

· The safety of turmeric has not been well evaluated for children or for women who are pregnant or nursing. Therefore, it is not recommended for use by such individuals or by women who have a chance of becoming pregnant.

Black pepper extract (piperine, Bioperine):

· The bioavailability enhancer piperine (from black pepper extract) added to many curcumin and turmeric supplements inhibits specific enzymes ("CYP" enzymes) which otherwise break down certain compounds, and it may also affect the permeability of the intestine. It may significantly increase the absorption of other compounds, so it would be best not to take if you are taking medications known to be metabolized by CYP enzymes. For example, it may inhibit the CYP3A4 enzyme, and small studies in people have shown that 20 mg piperine taken for 10 days significantly increased blood levels of the anti-seizure and nerve pain drug carbamazepine (Tegretol, Carbatrol, Epitol) and the nonsteroidal anti-inflammatory drug (NSAID) diclofenac (Voltaren , Cataflam, Flector) (Bedada, Drug Res (Stuttg) 2017; Bedada Xenobiotica 2016).(As noted above, curcumin may also inhibit this enzyme that can potentially affect a wide range of drugs).

· Piperine may also increase blood levels of drugs metabolized by the CYP1A1 enzyme: A study in people found 20 mg of piperine taken daily for 10 days increased blood levels of the muscle relaxant drug chlorzoxazone (Lorzone, Parafon) (Bedada, Xenobiotica 2017). Other drugs metabolized by this enzyme which could be affected include the bronchodilator theophylline (Theolair, Quibron-T, Theo-24), the antibiotic rifampin and bufuralol.

· Laboratory evidence suggests that piperine may have anti-platelet effects. It should be used with caution in people taking blood-thinning medication (Raghavendra, Prostaglandins Leukot Essent Fatty Acids 2009). It would seem prudent to discontinue piperine around the time of surgery.

· Large doses of piperine can potentially cause gastric irritation and bleeding. Even a single dose of black pepper (1.5 grams, equal to 3/4 teaspoon — which would contain about 30 to 100 mg of piperine) was shown to cause increased gastric secretion, gastric cell loss (exfoliation), and mucosal micro-bleeding in healthy volunteers -- similar to effects caused by 2 regular aspirin (655 mg) (Myers, Am J Gastroenterol 1987). Bioperine is sold as a single-ingredient supplement (typically with a warning not to take more than 20 mg per day). A CL member who took three 10 mg Bioperine (95% piperine) capsules daily (despite a label warning not to exceed two per day) to enhance curcumin bioavailability from turmeric, reported to ConsumerLab (8/20/17) that an endoscopy revealed bleeding in her stomach, but that stomach pain subsided a week after discontinuing the product. As noted earlier, turmeric/curcumin supplements that include piperine typically provide only 2.5 to 15 mg of piperine daily which, normally, should be safe.

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Information on this site is provided for informational purposes only. It is not an endorsement of any product nor is it meant to substitute for the advice provided by physicians or other healthcare professionals. The information contained herein should not be used for diagnosing or treating a health problem or disease. Consumers should inform their healthcare providers of the dietary supplements they take.

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