Potassium Supplements Review

Be Careful with Potassium Supplements! Problems Found. Tests and Reviews of Potassium Supplements & CL's Top Picks.

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

Last Updated : 10/16/2021 | Initially Posted: 05/01/2021Latest Update: Potassium for Kidney Stones?

Potassium Supplements reviewed by ConsumerLab.com

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Table of Contents

Summary

· What does potassium do? Potassium is a mineral and electrolyte that is essential for the proper functioning of the nervous system, skeletal system, heart, and metabolism, as well as maintaining normal blood pressure (see What It Is). Symptoms of potassium deficiency can include muscle weakness, irregular heartbeat, listlessness, mood changes, irrational behavior, nausea, and vomiting.

· Do I need to take a potassium supplement? Potassium supplements are typically used only to treat or prevent potassium deficiency. Sufficient amounts of potassium can easily be obtained through the diet, but people taking certain drugs or with conditions affecting the kidneys or gut may be deficient (see What to Consider When Using). Low potassium is also common among people hospitalized with COVID-19. Supplementing with potassium may also help to reduce high blood pressure. The citrate form of potassium may also reduce the risk of kidney stones (see What It Does).

· How much potassium should I take? For preventing potassium loss, potassium is often recommended at doses of 200 mg to 400 mg, taken 3 to 4 times daily (for a total daily dose ranging from 600 mg to 1,600 mg). For lowering blood pressure in people with hypertension, larger amounts are often used (3,000 mg per day) (see What to Consider When Using). Nearly all common forms of potassium are absorbed equally well (see What to Consider When Buying).

· Best potassium supplement? As discussed in What CL Found, problems were found with potassium supplements. One could cause you to take 2.5 times as much potassium as you might expect from its label. Pills of the other product would not fully break apart within the allotted time, suggesting the ingredients might be less available for absorption. None of the products exceeded limits for contamination with heavy metals (lead, cadmium, and arsenic), unlike our findings in 2016 when we discovered a significant amount of arsenic in a potassium supplement.

Among the products that passed testing, ConsumerLab.com chose three Top Picks.

· Safety and side effects of potassium supplements: Potassium from supplements may cause diarrhea, nausea, stomach pain, mild gas, and vomiting, which may be reduced by taking with meals. Less common side effects include confusion, irregular heartbeat and shortness of breath. People with kidney disease and people taking potassium-sparing diuretics, ACE inhibitors, or trimethoprim/sulfamethoxazole should not take potassium supplements without medical supervision (see Concerns and Cautions).

What It Is:

Potassium is an essential mineral. It is found in foods and supplements in many forms, including potassium bicarbonate, potassium citrate, potassium gluconate, potassium acetate and (particularly in some salt substitutes) as potassium chloride (See ConsumerTips: What to Consider when Buying for more information about forms of potassium). Potassium is also used in supplements to stabilize other key compounds, such as in potassium iodide supplements where potassium stabilizes iodine as a radioprotective agent (see separate review of Radioprotective Agents).

What It Does:

Potassium deficiency
Potassium, like sodium and chloride, is an important electrolyte involved in the proper functioning of the nervous system, skeletal system, cardiac muscle, and metabolism, as well as maintaining normal blood pressure.

Although most people get enough potassium from their diets, some research has noted a decline in potassium levels in people in the U.S. An analysis of over 50,000 men, women, and children (ages 12 to 80) from 1999 to 2016 found that average annual blood levels of potassium decreased (from 4.14 mmol/L to 3.97 mmol/L) and the prevalence of potassium deficiency increased by 7.3% and was more common in non-Hispanic black than non-Hispanic white individuals. The researchers suggested that a decline of potassium in crop soil and fertilizer, as well as increased consumption of processed foods and decreased consumption of fruits and vegetables may play in these trends (Sun, J Am Coll Nutr 2020).

Normal blood levels of potassium range between 3.6 and 5.0 mmol/L (NIH Fact Sheet 2020).

Potassium supplements are typically used only to treat or prevent potassium deficiency (hypokalemia) caused by excessive potassium loss. Potassium deficiency can result from the use of diuretic drugs ("water pills") to treat high blood pressure and can also occur in cases of prolonged vomiting, diarrhea or laxative abuse. Deficiency can cause muscle weakness, irregular heartbeat, listlessness, mood changes, irrational behavior, nausea, and vomiting. Some research indicates that potassium may help reduce hypertension -- particularly in African-Americans and people who consume too much sodium.

Potassium deficiency may also cause muscle spasms, but there are no published, double-blind clinical studies on the effects of potassium supplementation on muscle cramps. Furthermore, nighttime muscle cramps and exercise-related muscle cramps do not appear to be related to potassium levels (Allen, Am Fam Physician 2012). A small study in India among people with moderate to severe restless leg syndrome suggested a benefit from taking a daily dose of 391 mg of potassium (as 1,080 mg of potassium citrate): After one month, the majority of people reported having no symptoms (Rauf, Pharm Pharmacol Int J 2016). However, this study did not include a control group, so it's not possible to draw conclusions from it.

Kidney stone disease
Taking certain forms of potassium may reduce the risk of kidney stones.

A clinical study found that patients who took 6,480 mg (or 60 milliequivalents [mEq]) of potassium citrate daily (divided into three equal doses, each taken after a meal) had no stone recurrence after one year, compared to a 28.5% stone recurrence rate in patients who did not take potassium citrate (Soygur, J Endourol 2002).

Some of the products reviewed by ConsumerLab.com (below) provide potassium citrate, although the suggested serving sizes are much lower than those used to prevent kidney stones: Most potassium citrate supplements typically provide 99 mg of potassium from 258 mg (2.4 mEq) of potassium citrate, so you would need to take many times the suggested daily serving to achieve therapeutic levels of citrate. It is important to understand that it is not the potassium that is helpful but the citrate portion of the molecule, as it is the citrate that interferes with calcium stone formation. Foods and beverages rich in citrate, such as citrus and melon, are, for this reason, often recommended for people with kidney stone disease.

Another clinical study found that two tablets containing 1,954 mg of a patented potassium complex taken three times daily (providing a daily total of 1,638 mg potassium, 252 mg magnesium and 3,971 mg citrate) for up to three years reduced the risk of kidney stone recurrence by 85% in people with active kidney stone disease compared to placebo (Ettinger, J Urol 1997). However, be aware that potassium citrate and magnesium citrate can interfere with certain drugs or have other side effects (see the Concerns and Cautions section of this Review and the Magnesium Review) so it's best to consult your healthcare provider if you are considering taking them at these doses.

Potassium phosphate may also help people with kidney stone disease because the phosphate decreases excessive calcium in the urine in people with hypercalciuria, the most common cause of calcium kidney stones. A small clinical study found 2,496 mg of potassium (as potassium phosphate) taken as four tablets twice daily for four years reduced urinary calcium by 30 to 35% in patients with absorptive hypercalciuria (Heller, J Urol 1998). [Note: In studies, doses of potassium are usually listed in units of "milliequivalents" (mEq), but we have converted these to milligrams (mg), the unit used on most supplement labels.]

Several case reports suggest that potassium bicarbonate may help dissolve kidney stones and prevent recurrence, although this does not seem to have been tested in clinical trials. A 59-year-old man with kidney stones who took 1,173 mg (30 mEq) of potassium as potassium citrate and potassium bicarbonate one to three times daily to increase urine pH levels to between 6.5 and 6.8 experienced reduction in stone size after 4 months and complete disappearance of stones after 7 months (Barbera, Arch Ital Urol Androl 2016). According to another report, a man with recurrent kidney stones did not experience any additional stones over an 18-month period after starting to take 782 mg (20 mEq) of potassium as potassium bicarbonate two to three times daily along with allopurinol (100 mg three times daily) (Pak, Kidney Int 1986).

Coronavirus
Potassium will not prevent COVID-19, the infection caused by the SARS-CoV-2 coronavirus, but low potassium levels have been noted in people hospitalized with COVID-19. Doctors in China reported that among a group of 175 patients hospitalized with COVID-19, 69 (39%) had hypokalemia (low potassium in the blood) and another 39 (22%) had severe hypokalemia. Supplementing with about 3 grams of potassium daily helped correct these deficiencies in most patients. The presence of underlying disease, particularly hypertension, was associated with the severity of hypokalemia. On the other hand, there was no association between hypokalemia and common upper respiratory symptoms, such as cough and runny nose (i.e., if those are your only symptoms, you probably don't have to worry about your potassium level) (Chen, preprint in medRxiv 2020 -- Not yet peer-reviewed). A study of 290 hospitalized patients with confirmed COVID-19 in Italy found that although hypokalemia was common, it tended to be mild and was treatable with oral potassium supplements. It was not associated with poor outcomes or mortality (Alfano, preprint in medRxiv 2020 -- Not yet peer-reviewed).

The apparent reason for hypokalemia in COVID-19 is that the point of entry into cells for the coronavirus SARS-CoV-2 is an enzyme on cell surfaces called angiotensin I converting enzyme 2 (ACE2). ACE2 is found on many types of cells, including those in the lungs, intestines, kidneys, and heart. It normally helps regulate blood pressure through effects on sodium and potassium. The virus inactivates ACE2, leading to excretion of potassium. This explanation was further supported by the finding of excess potassium in the urine of patients with hypokalemia, indicating that the potassium loss is mainly through the kidneys (from potassium it normally filters from the blood) as opposed to diarrhea -- which is also common in COVID-19. There are hypothetical concerns that taking prescription ACE-inhibitors and angiotensin receptor-blockers (ARBs) may increase ACE2 on cell surfaces, potentially increasing the risk of developing severe COVID-19 (Fang, Lancet 2020; Diaz, J Trav Med 2020) but there are also cautions not to stop taking such medications as they not only control high blood pressure but may helpful in treating COVID-19 (Danser, Hypertension 2020; de Simone, Eur Soc Cardio 2020).

Quality Concerns and Tests Performed:

Neither the FDA nor any other federal or state agency routinely tests supplements for quality prior to sale. Consequently, ConsumerLab.com tested potassium products to determine if they contained listed amounts of potassium. All products were tested for contamination with the heavy metals lead, cadmium, and arsenic. Standard tablets and caplets were also tested to check that they could disintegrate ("break apart") properly (see Testing Methods and Passing Score).

What CL Found:

Among the 10 potassium supplements ConsumerLab.com selected and tested, eight met ConsumerLab.com's quality standards and FDA labeling requirements. Through ConsumerLab.com's voluntary Quality Certification Program, in which products undergo the same testing, an additional three products were found to meet CL's quality standards.

Problems found:
Two products failed ConsumerLab's review:

· Nature's Way Krebs Magnesium Potassium Complex tablets would not fully break apart within the allotted 30 minutes in disintegration testing, suggesting its ingredients could be less available for absorption.

· BulkSupplements.com Potassium Chloride powder had incorrect "Suggested Use" information on its label that could cause you take two and a half times as much potassium as expected from the label. The label suggests taking "200 mg (about 1/10) once daily." The online webpage for the product showed that this refers to 1/10^th of a teaspoon. But the typo (leaving out the word "teaspoon") is not why this product failed our review. We found that a teaspoon of the powder weighed approximately 5,200 mg, so 1/10^th of a teaspoon would provide 520 mg of potassium chloride, not 200 mg. As potassium chloride is only 52% potassium, this would provide 270 mg of potassium per 1/10^th teaspoon serving, not the 105 mg that the Supplement Facts panel claims per serving.

None of the products exceeded limits for contamination with heavy metals (lead, cadmium, and arsenic) -- unlike results in 2016, when CL discovered a significant amount of arsenic in Nature's Sunshine Combination Potassium. A daily serving contained more arsenic than permitted in an entire liter of water by the EPA. The arsenic in it exceeded the California limit for potential reproductive harm as well as its limit for arsenic as a carcinogen. A recommended daily serving of six capsules of Nature's Sunshine Combination Potassium contained 56.6 mcg total arsenic, 26.6 mcg of which is inorganic arsenic (thought to be the most toxic form of arsenic). The arsenic was likely from plant-based ingredients, including kelp. (See ConsumerLab.com's Kelp Supplements Review, which includes tests for contamination with arsenic and other heavy metals, as well as amounts of iodine -- an essential element found in kelp.)

Potassium per serving:
All of the products, other than BulkSupplements.com, contained their listed amounts of potassium per serving. As shown below, most of the supplements provided 99 mg of potassium per serving (typically one caplet or capsule), although some provided more, with NOW Potassium Chloride Powder providing the most at 365 mg of potassium per 1/8 teaspoon.

Potassium Per Serving

Cost:
Potassium is typically inexpensive. As shown below, the cost to get 99 mg of potassium from each product was less than one cent from powdered products and, from 1 cent to 12 cents from tablets, caplets, and capsules. The most expensive product happened to be the only one that was Not Approved (due to poor disintegration, as noted above), Nature's Way Krebs Magnesium Potassium Complex, which provided 100 mg of potassium and 250 mg of magnesium (both from a combination of citrate and malate forms) per two vegan tablet serving for 24 cents. Products with multiple ingredients often cost more, although this product cost far more than Vitacost Potassium Magnesium, providing 120 mg of potassium and 40 mg of magnesium (both in the aspartate form) from two capsules.

Cost Per 99 mg Potassium

Top Picks:

To treat potassium deficiency or for potassium maintenance:
As noted in ConsumerTips, more than 90% of potassium is absorbed in the gastrointestinal tract, and nearly all of the common forms of potassium are absorbed equally well. With that in mind, among the product Approved in our tests, it is fine to choose a product that provides the potassium you need at lowest cost. You'll have to adjust the number of servings you take to provide the amount of potassium that you need.

· Potassium Pills: (tablets, caplets, and capsules), the lowest cost Approved product, and our Top Pick, is Member's Mark Potassium, providing 99 mg of potassium (from potassium gluconate) per caplet for about one cent. Although there is no compelling reason to spend more, any of the other Approved products would be fine and some cost only a little more, such as Swanson Potassium Citrate (2 cents per 99 mg of potassium, from potassium citrate).

· Potassium Powders: If you have trouble swallowing pills or need an amount of potassium that would necessitate a taking a great number of pills, you may prefer a potassium powder that you mix with water or another beverage. Our Top Pick among the powders that we tested is NOW Potassium Chloride Powder: A 1/8 teaspoon serving provides a whopping 365 mg of potassium for only 2 cents. This is to be mixed with 8 ounces of water. We tried this and the liquid tasted mildly bitter because NOW is made from potassium chloride, which is known to be more bitter than other forms, such as gluconate, although no form tastes great (see "Forms of potassium").

To get magnesium with potassium:

· If you need some magnesium as well as potassium (see What to Consider When Using -- Taking magnesium with potassium), Vitacost Potassium & Magnesium provides 40 mg of magnesium and 120 mg of potassium for just 5 cents per two-capsule serving and is our Top Pick among potassium-magnesium combination products. (You can also just buy a separate magnesium supplement — see ConsumerLab.com's Magnesium Supplements Review).

Test Results by Product:

Listed alphabetically below are the test results for 13 potassium supplements (including two potassium-magnesium combination supplements). Ten of these were selected by ConsumerLab.com and three others (each indicated with a CL flask) were tested at the request of their manufacturers/distributors through ConsumerLab.com's Quality Certification Program.

Products listed as "Approved" met their label claim and ConsumerLab.com's standards for potassium supplements. Also shown for each product is the serving size recommended on the label, the form of potassium, and the amount of potassium in the recommended serving. In the 4^th column is the price paid, cost per suggested serving, and calculated cost of a 99 mg serving. Notable features are in the 5^th column. The full list of ingredients is in the last column on the left.

Results of ConsumerLab.com Testing of Potassium Supplements

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

Approval Statusⓘ

Product Name

Serving Size, Claimed Amount & Form of Potassiumⓘ

Pill Sizeⓘ

Heavy Metalsⓘ

Disintegration

Suggested Daily Servings on Label

Cost for Suggested Serving

[Cost Per 99 mg Potassium]

Price Paid

Notable Features

Full List of Ingredients Per Serving

Potassium Pills:

APPROVED

Bluebonnet Potassium 99 mg

Mfd. by Bluebonnet Nutrition Corporation

1 vegetable capsule

99 mg
✔
Potassium aspartate

Large vegetable capsule

Metals: Pass

Disintegration: NA

Take one capsule daily or as directed by a healthcare practitioner.

$0.12/vegetable capsule

[$0.12]

$10.36/90 vegetable capsules

Non-GMO. Vegan. Kosher. Gluten Free. Free of milk, egg, crustacean shellfish, tree nuts, peanuts, wheat and soybeans. Also free of corn, yeast, gluten, barley, rice, sodium and sugar.

1 vegetable capsule
Potassium (as potassium aspartate) 99 mg.

Other Ingredients: Kosher vegetable capsules, vegetable cellulose, vegetable magnesium stearate, silica.

APPROVED

CVS Health™ Potassium Gluconate 595 mg

Dist. by CVS Pharmacy, Inc.

1 caplet

99 mg
✔
Potassium gluconate

Medium/large caplet

Metals: Pass

Disintegration: Pass

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

$0.05/caplet

[$0.05]

$5.49/100 caplets

No yeast, wheat, gluten, milk or milk derivatives lactose, sugar, preservatives, soy, artificial color, artificial flavor, salt.

1 caplet
Potassium (from 595 mg Potassium Gluconate) 99 mg.

Other Ingredients: Microcrystalline Cellulose, Croscarmellose Sodium, Vegetable Magnesium Stearate, Stearic Acid and Silica.

APPROVED

Designs For Health® K+2 Potassium

Mfd. by Designs for Health, Inc.

1 vegetarian capsule

300 mg
✔
Potassium bicarbonate, potassium glycinate complex

Large vegetarian capsule

Metals: Pass

Disintegration: NA

Take one capsule per day with a meal, or as directed by your health care practitioner.

$0.24/vegetarian capsule

[$0.08]

$28.36/120 vegetarian capsules

Does not contain gluten, dairy, soy or GMOs.

1 vegetarian capsule
Potassium (as Potassium Bicarbonate, Potassium Glycinate Complex) 300 mg.

Other Ingredients: Cellulose (capsule), vegetable stearate.

APPROVED

H-E-B® Potassium Gluconate

Dist. by H-E-B®

1 caplet

99 mg
✔
Potassium gluconate

Medium/large caplet

Metals: Pass

Disintegration: Pass

For Adults, Take One (1) Caplet Daily, Preferably With A Meal.

$0.03/caplet

[$0.03]

$2.70/100 caplets

Gluten Free.

1 caplet
Potassium (as Potassium Gluconate) 99 mg.

Other Ingredients: Cellulose (Plant Origin). Contains <2% of: Croscarmellose, Silica, Vegetable Magnesium Stearate, Vegetable Stearic Acid.

APPROVED

Top Pick

for pills

Member's Mark [Sam's Club] Potassium

Dist. by Sam's West, Inc.

1 caplet

99 mg
✔
Potassium gluconate

Medium/large caplet

Metals: Pass

Disintegration: Pass

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

$0.01/caplet

[$0.01]

$7.34/500 caplets

No Sugar. No Synthetic Dyes. No Milk Or Milk Derivatives. No Lactose. No Wheat. No Artificial Flavors. No Preservatives. No Gluten. No Yeast. No Soy. No Sodium (Less Than 5 mg Per Serving).

Product of China and Germany.

1 caplet
Potassium (as Potassium Gluconate) 99 mg.

Other Ingredients: Cellulose (Plant Origin). Contains <2% of: Croscarmellose, Silica, Vegetable Magnesium Stearate, Vegetable Stearic Acid.

NOT APPROVED

Nature's Way® Krebs Magnesium Potassium Complex

Dist. by Nature's Way Brands, LLC

$ Price Check

2 vegan tablets

100 mg
✔
Potassium citrate, potassium malate

Large vegan tablet

Metals: Pass

Disintegration: Required more than 30 minutes
(Needed 40 minutes to fully disintegrate)

Take 2 tablets daily.

$0.24/2 vegan tablets

[$0.24]

$14.49/120 vegan tablets

2 vegan tablets

Magnesium 250 mg, sodium 5 mg

Vegan. Gluten Free. No yeast-derived ingredients, wheat corn, soy, dairy products, or artificial colors.

2 vegan tablets
Calories 5, Total Carbohydrate 2 g, Magnesium (as magnesium citrate and malate chelates) 250 mg, Sodium 5 mg, Potassium (as potassium citrate and malate) 100 mg.

Other Ingredients: Cellulose, more...

APPROVED

Puritan's Pride® Potassium 99 mg

Mfd. by Puritan's Pride, Inc.

1 caplet

99 mg
✔
Potassium gluconate

Medium/large caplet

Metals: Pass

Disintegration: Pass

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

$0.07/caplet

[$0.07]

$6.74/100 caplets

Vegetarian. No Artificial Color, Flavor or Sweetener, No Preservatives, No Sugar, No Starch, No Milk, No Lactose, No Soy, No Gluten, No Wheat, No Yeast, No Fish. Sodium Free.

1 caplet
Potassium (as Potassium Gluconate) 99 mg.

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

APPROVED

Rexall® Potassium 99 mg

Dist. by Dolgencorp, LLC

1 caplet

99 mg
✔
Potassium gluconate

Medium/large caplet

Metals: Pass

Disintegration: Pass

For Adults, Take One (1) Caplet Daily, Preferably With A Meal.

$0.04/caplet

[$0.04]

$2.25/60 caplets

No Gluten, No Yeast, No Wheat, No Milk or Milk Derivatives, No Lactose, No Sugar, No Preservatives, No Soy, No Artificial Color, No Artificial Flavor, No Sodium.

1 caplet
Potassium (as Potassium Gluconate) 99 mg.

Other Ingredients: Cellulose (Plant Origin). Contains <2% of: Croscarmellose, Silica, Vegetable Magnesium Stearate, Vegetable Stearic Acid.

APPROVED

Swanson® Potassium Citrate

Dist. by Swanson Health Products

1 capsule

99 mg
✔
Potassium citrate

Medium/large capsule

Metals: Pass

Disintegration: NA

Take one capsule per day with food and water.

$0.02/capsule

[$0.02]

$2.39/120 capsules

None.

1 capsule
Potassium (from potassium citrate) 99 mg.

Other Ingredients: Rice flour, gelatin, magnesium stearate.

APPROVED

TwinLab® Potassium Caps

Dist. by Twinlab Corporation

1 capsule

99 mg
✔
Potassium citrate, potassium aspartate

Medium/large capsule

Metals: Pass

Disintegration: NA

Take one capsule daily.

$0.05/capsule

[$0.05]

$9.85/180 capsules

No artificial colors, flavors, or preservatives added.

1 capsule
Potassium (as Potassium Citrate & Aspartate) 99 mg.

Other Ingredients: Gelatin, Potato Starch. Contains 2% or less of: Medium Chain Triglycerides, Magnesium Stearate, Silicon Dioxide.

APPROVED

Top Pick

for a magnesium & potassium combination

Vitacost® Potassium & Magnesium

Dist. by Vitacost.com, Inc.

2 capsules

120 mg
✔
Potassium aspartate

Large capsule

Metals: Pass

Disintegration: NA

Take 2 capsules daily with food or as directed by a healthcare professional.

$0.05/2 capsules

[$0.04]

$5.11/200 capsules

2 capsules

Magnesium 40 mg

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

2 capsules
Magnesium (as magnesium aspartate) 40 mg, Potassium (as potassium aspartate) 120 mg.

Other Ingredients: Gelatin, microcrystalline cellulose, more...

Potassium Powder:

NOT APPROVED

Bulk-
Supplements.com Potassium Chloride

Dist. by Bulk-
Supplements.com

Claimed 200 mg potassium chloride per 1/10 tsp, but found 520 mg

Claimed 105 mg potassium per 1/10 tsp, but found 270 mg

Powder in pouch

Metals: Pass

Disintegration: NA

Take 200 mg (about 1/10 tsp) once daily, or as directed by a physician.

$0.01 per 1/10 tsp

[<$0.01]

$17.96/35.3 oz [1,000 g] pouch (claims 5,000 servings, but found 1,923 servings)

Free of: Sugar, soy, dairy, yeast, gluten or additives.

1/10 tsp
Potassium (as Potassium Chloride) 105 mg (found 270 mg).

Other Ingredients: None.

APPROVED

Top Pick

for powders

NOW® Potassium Chloride Powder

Dist. by Now Foods

$ Price Check

1/8 tsp [700 mg potassium chloride]

365 mg potassium
✔

Powder in bottle

Metals: Pass

Disintegration: NA

Take 1/8 teaspoon with food. Can be take 1 to 3 times daily in separate servings.

$0.02 per 1/8 tsp

[<$0.01]

$5.70/8 oz [338 g] bottle (approx. 324 servings)

Non-GMO. Sodium Free. Vegetarian/Vegan. Not manufactured with yeast, wheat, gluten, soy, milk, egg, fish, shellfish or tree nut ingredients.

1/8 tsp
Potassium (from Potassium Chloride) 365 mg.

Other Ingredients: Magnesium carbonate (as flow agent).

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.

ConsumerTips™:

What to Consider When Buying:
When checking the amount of potassium in a product, be sure to carefully read the Supplement Facts panel (typically on the side or back label) because the names of some potassium products may be confusing. For example, a product named "Potassium Gluconate 595 mg" will actually contain only about 99 mg of actual potassium (or "elemental" potassium). This is because potassium makes up far less than half of the weight of most potassium compounds. For example, potassium makes up only 16.7% of the weight of potassium gluconate, 38.3% of potassium citrate and 52% of potassium chloride. Also note that potassium dosage is sometimes calculated in milliequivalents (1 milliequivalent equals 39.09 milligrams of potassium).

When sold as a dietary supplement, potassium products typically contain up to 99 mg of elemental potassium per pill. (Interestingly, this is due to an old regulation prohibiting solid dosage forms from exceeding this amount without a warning; however, that regulation is no longer in effect, as it was superseded by other law in 1994.) However, products containing several hundred milligrams of elemental potassium per pill can now be found, as are products offering similarly large doses from liquids, powders, granules, or dissolving tablets for preparation in a solution or suspension. Such products may be preferable when high doses are needed because pills providing that much potassium would need to be extremely large and bulky.

Forms of potassium:
More than 90% of potassium is absorbed in the gastrointestinal tract and nearly all of the common forms of potassium are absorbed equally well. Potassium gluconate has a less bitter taste than some other forms. When shopping you will find that prices range from 1 cent to over 20 cents for the same amount of potassium (99 mg) -- so it's helpful to compare prices.

What to Consider When Using:
There is no recommended daily allowance (RDA) for potassium, but a daily Adequate Intake (AI) has been established. The AI of potassium is 2,000 mg for those ages 1 to 3, 2,300 mg for ages 4 to 8, 2,500 mg and 2,300 mg, respectively, for boys and girls ages 9 to 13, 3,000 mg and 2,300 mg, respectively, for young men and women ages 14 to 18, and 3,400 mg and 2,600 mg for men and women. For women who are pregnant, the AI is 2,900 mg, or 2,600 mg if under 19. For women who are breast feeding it is 2,800 mg, or 2,500 if under 19.

Note that the above recommendations were introduced in March 2019 and are lower than previous recommendations published in 2005. For example, the previous AI for adults was 4,700 mg, but this was reduced by 1,300 mg for men and 2,100 mg for women. The reason for the reduction in the AIs is a change in how these values are set so that they focus specifically on nutritional adequacy in healthy individuals. Higher total intakes may reduce high blood pressure for some (see What It Does and Dosage), but there is currently insufficient evidence for intakes to be established for that purpose (National Academies 2019). Be aware that the "percent of Daily Value" figures that appear for potassium on some food and supplement labels remain based on now outdated 2005 recommendations or even older DVs, since small supplement manufacturing companies were given until January 2021 to update their DV information to reflect DVs set in 2016.

Tolerable Upper Intake Levels (ULs) have not been established for potassium because your body excretes excess potassium as long as your kidneys are healthy. Caution against high intakes is warranted for people with, or at risk of, compromised kidney function. Typically, people requiring dialysis for kidney disease are advised to restrict potassium intake to 2,000 mg daily. However, getting too little potassium can be a concern as well (see Concerns and Cautions section for details).

Getting it from food: Foods especially rich in potassium (containing more than 300 milligrams of potassium per serving) are beans (lima, black bean, kidney beans), acorn or butternut squash, potatoes (with skin), spinach, bananas, orange juice, coconut water, avocados, lima beans, cantaloupes, peaches, tomatoes, flounder, salmon, and cod. For example, one cup of kidney beans provides 2,587 mg of potassium, one large white baked potato with skin provides 1,627 mg, one filet (about 100 g) of red sockeye salmon provides 1,037 mg, and one cup of mashed banana provides 806 mg. Some salt substitutes also contain high amounts of potassium. (An extensive listing of potassium levels in foods is available from the USDA.)

Dosage: For preventing potassium loss, the daily dose for adults is about 200 to 400 mg (approx. 5 to 10 milliequivalents) taken three to four times a day, for a total daily dose ranging from 600 mg to 1,600 mg per day. For treating potassium deficiency, approximately double the dose is used. A physician should determine children's doses. When used to reduce blood pressure in people with hypertension, large amounts of potassium supplementation are typically used -- about 3,000 mg per day (Whelton, JAMA 1997).

Because most supplements don't contain more than 99 mg of potassium per tablet, you may have to take a large number of pills to reach the higher doses. You should consider using a powder or other dosage forms if you wish to avoid taking a large number of pills.

Storage:
It is best to store potassium supplements in a closed container away from excess heat and moisture.

Taking magnesium with potassium:
About 50% of individuals with chronically low blood levels of potassium also have magnesium deficiency. This is combination of deficiencies is most often due to the use of loop or thiazide diuretics, but can also be due to diarrhea, alcoholism, kidney disease, or kidney toxicity from medications. In such cases, if the magnesium deficiency is not also addressed, it may be harder to correct the potassium deficiency (Huang, JASN 2007). Consequently, magnesium is sometimes given along with potassium and they are combined in supplements. (See the Magnesium Supplements Review for more information about magnesium and tested supplements.) Some potassium products contain magnesium stearate, which improves the consistency of the product during manufacturing, but is not a significant source of magnesium.

Reducing salt intake by substituting potassium
On average, adults in the U.S. consume almost twice the recommended limit for sodium, which is 2,300 mg per day. In addition to limiting salt intake, "lite" salts (in which about half of the sodium is replaced by potassium) and salt substitutes (which contain no sodium and are, most commonly, potassium chloride and/or potassium bitartrate) can be a good way to reduce sodium intake as well as add more potassium to your diet.

Replacing sodium with potassium has been shown in studies to modestly improve blood pressure in people with hypertension, reducing systolic and diastolic blood pressure by an average of about 4.9 mm Hg and 1.5 mm Hg, respectively (Raquel, Hypertension 2020). It's important to note that the products used in the studies contained between 25% and 67% potassium, with more than half of the products containing less than 30% potassium (similar to some "lite" salt products), but all still contained a significant amount of sodium chloride.

None of these studies, however, were conducted in the U.S., where table salt used in the home for cooking is not the major contributor of sodium in the diet (most comes from processed foods). Nevertheless, the impact of even modest improvement can be significant. In a large 5-year study in China, among 15,000 adults with a history of stroke or who were age 60 or older and had high blood pressure (most of whom were taking blood-pressure lowering medication) use of a salt that was 75% sodium chloride and 25% potassium chloride for cooking and seasoning resulted in 14% reduction in risk of stroke, 13% reduction in risk of major cardiovascular events, and 12% reduction in risk of death compared to those who consumed regular salt. In addition, there seemed to be no increase in adverse events due to the extra potassium (Neal, N Engl J Med 2021).

Be aware that although potassium-containing salts are likely safe for most healthy people, they should not be used by people with kidney disease without medical supervision, and people with type 1 or type 2 diabetes, coronary artery disease, or heart failure, and those taking potassium-sparing diuretics and other medications that impair potassium excretion, including ACE inhibitors should also consult with their physician regarding use of salt substitutes. Some people using salt substitutes have reported experiencing gastrointestinal symptoms.

"Lite" salts and salt substitutes containing potassium are more expensive than regular table salt, which costs only about 5 cents per ounce. "Lite" salts cost about 18 to 23 cents per ounce and salt substitutes cost about 50 to 90 cents per ounce. They may also have an unpleasant metallic taste, or aftertaste, and when used in cooking, may make foods taste "less salty," although some studies report that cooking with a product in which 30% of sodium chloride is replaced by potassium chloride may have a similar flavor to regular salt (Yin, JMIR Public Health Surveill 2021).

Below are some good options among "lite" salts and salt substitutes sold in the U.S.

For someone who needs to reduce, but not eliminate, salt, this is a good option:

Morton Lite Salt Mixture — One-quarter teaspoon contains 290 mg of sodium (about half that of regular salt) and 590 mg of potassium from potassium chloride and potassium iodide, and 60 mcg of iodine. It has received mostly good reviews for taste on Amazon, with several people commenting that it tastes like salt, but is "less salty." Cost (11 oz cannister): $1.98 at Walmart and $2.59 at Publix and through Instacart.

For someone who wants to replace salt, these are good options:

NoSalt Original Sodium-Free Salt Alternative — One-quarter teaspoon contains 640 mg of potassium from potassium chloride and potassium bitartrate. It does not contain sodium chloride or iodine. Like other salt substitutes, it has mixed reviews for taste, but overall reviews are more positive then with some other brands. Cost: (11 oz cannister): $4.94 at Walmart, $6.31 at Publix and $9 to $10 dollars from Amazon.

Morton Salt Substitute — One-quarter teaspoon contains 610 mg of potassium from potassium chloride. It does not contain sodium chloride or iodine. There are very mixed reviews regarding taste on Amazon. Cost (3.12 oz container): $2.89 at Food Lion and $6.99 on Amazon.

MySalt — One-quarter teaspoon contains 356 mg of potassium from potassium chloride, making it a good option if you prefer a potassium salt substitute with less potassium than other products. It does not contain sodium chloride or iodine. There are many, mostly positive reviews from customers, with some stating it tastes just like salt, and others that it has a slight after-taste, but much less so than other salt substitutes. It appears to be sold only through the company's website, which includes other salt-free products, such as salad dressing, sauces, taco and chili mixes. Cost (3 oz container): $6.89 on mysaltsub.com.

Concerns and Cautions:

Potassium from supplements may cause diarrhea, nausea, stomach pain, mild gas, and vomiting, although these side effects may be reduced when potassium is taken with meals. More serious side effects, although less common, include confusion, irregular heartbeat, numbness or tingling in hands, feet, or lips, shortness of breath, anxiety, and tiredness or weakness. They can also cause more severe stomach pain, chest or throat pain (when swallowing so be sure to take with water).

Individuals with kidney disease cannot properly control levels of electrolytes in the body. In this situation the use of potassium (or any other mineral) can be dangerous and should be used only under medical supervision. People requiring dialysis for kidney disease are advised to restrict potassium intake to about 2,000 mg daily. However, getting too little potassium may be a concern as well. A study among 415 people undergoing dialysis (average age 56) found that those who consumed only about 543 mg of potassium per day had a two-fold greater mortality risk compared to those who consumed about 2,600 mg. The risk was greater in people over 55-years-old compared to younger people (Narasaki, J Renal Nutr 2020).

Individuals taking potassium-sparing diuretics (such as spironolactone), ACE inhibitors (such as captopril), or trimethoprim/sulfamethoxazole should not take potassium supplements without medical supervision as dangerous levels of potassium may develop. Excessive use of salt substitutes that contain potassium chloride can add to the potassium load. Liberal use of these products in people with kidney disease can cause dangerously high levels of potassium to build in the bloodstream.

Higher intakes of potassium have been associated with an increased risk premenstrual syndrome (PMS). According to a large study of women in the U.S., those who consumed higher amounts of potassium from their diet (median intake 3,717 mg daily) had a 46% higher risk of premenstrual syndrome (PMS) compared to those consuming less potassium (median intake 2,319 mg/day) (Chocano-Bedoya, Am J Epidem 2013).

A case of leg cramps was reported in a women in Japan who consumed a mango (a potassium-rich fruit) every night before bed for one month and developed elevated potassium levels. The cramps resolved after she stopped eating mangos and her potassium levels returned to normal (Abe, Case Rep Neurol Med 2012).

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.

Latest Clinical Research Updates for Potassium

Potassium for Kidney Stones?

9/28/2021

Can taking certain forms of potassium help dissolve or prevent kidney stones? Find out in the What It Does section of our Potassium Supplements Review. Also see our Top Picks among potassium supplements.

Potassium and Dialysis

11/04/2020

People on dialysis are often told to restrict potassium intake, but getting too little potassium can also be a problem according to a new study. Get the details in the Concerns and Cautions section of our Potassium Supplements Review. Also see our Top Picks for potassium supplements.

Low Potassium in COVID-19 Patients

6/20/2020

Patients hospitalized with COVID-19 have often been found to have low potassium levels. Should you be concerned? Learn more in the COVID-19 section of the Potassium Supplements Review. Also see our Top Picks among potassium supplements.

Potassium Levels Decline

5/19/2020

An analysis of blood samples of thousands of Americans suggests a slight decline in potassium intake. Find out what may be causing this in the update to the What It Does section of the Potassium Supplements Review. Also see our Top Picks for potassium supplements.

New Potassium Recommendations

3/22/2019

The amount of potassium needed to achieve nutritional adequacy was officially reduced this month for all ages. Find out why and get the new recommendations in the What to Consider When Using section of the Potassium Supplements Review. Also see our Top Picks for potassium supplements.