Ashwagandha Supplements Review
Find the Best Ashwagandha
Supplement. Only 56% of Ashwagandha Products Pass Tests.
Medically reviewed and
edited by Tod Cooperman, M.D. 
Last Updated
: 11/29/2021 | Initially Posted:
06/16/2018Latest Update: Ashwagandha for Stress?
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Table of Contents
Summary
·
Does ashwagandha work? Preliminary studies suggest that
ashwagandha may help reduce anxiety, improve physical and cognitive performance, and have other
benefits. However, larger studies are needed for confirmation.
·
How to choose an ashwagandha supplement? When choosing an ashwagandha product, look for a
root powder or a root extract containing, respectively, at least 0.3% and 1.5%
of withanolides — key marker compounds which may also
play a role in the herb's activity.
·
How much ashwagandha to take? Daily dosage for a root powder is typically 1
to 6 grams (1,000 mg to 6,000 mg). For extracts it is 500 mg to 1,500 mg. A
daily dose should provide at least 6 mg of withanolides
— typically between 10 mg and 30 mg has been used in most studies.
·
What did CL's tests of ashwagandha supplements find? Many products
contained lower amounts of withanolides than expected
and only 56% of the products selected for testing were Approved. The amount of withanolides in a suggested daily serving ranged from just
0.57 mg to as much as 95.3 mg. The cost to obtain 6 mg of withanolides
ranged from just 7 cents to $1.24. Price was not an indicator
of quality. (See What CL Found).
·
Best ashwagandha products? Several products were Approved for Quality
and provide doses of withanolides consistent with
efficacy in clinical studies. Among these, one product was selected as a Top Pick,
offering superior strength and at low cost for withanolides.
Several additional products represent good, well-priced alternatives.
·
Ashwagandha safety and side effects: Ashwagandha is
generally well tolerated but headache and gastrointestinal or allergic
reactions can occur. Although rare, liver injury can occur. Ashwagandha may
potentially lower blood pressure and blood sugar levels, and affect thyroid
hormone levels. It should not be used by women or who are pregnant or nursing.
For more details, see Concerns and Cautions.
What It Is:
Ashwagandha
(Withania somnifera)
is an herb grown in India and in certain regions of Nepal. The roots contain withanolides, which are compounds thought to be responsible
for some of the herb's effects (Prabhakaran, Pak J Pharm Sci 2012).
Ashwagandha is sometimes referred to as "Indian ginseng" because it
is thought to have similar "adaptogen" qualities, such as modulating
the immune system and supporting the body's response to stress. It is also
sometimes referred to as "winter cherry," but should not be confused
with another plant, Physalis alkekengi,
which is also commonly referred to as "winter cherry."
What It Does:
A number of small, short-term studies suggest a variety of
potential uses for ashwagandha, but larger, long-term studies are needed to
confirm these findings.
Anxiety
Clinical studies suggest that ashwagandha can reduce anxiety, although some
studies have shown only modest benefits. One randomized, double-blind study of
75 middle-aged adults with moderate to severe anxiety found
that anxiety was dramatically reduced, and fatigue, motivation and
concentration significantly improved, in those who received 300 mg of
ashwagandha root extract (standardized to 1.5% withanolides)
twice per day (a total daily dose of 600 mg ashwagandha extract containing 9 mg
of withanolides), plus a daily multivitamin for 12
weeks (Cooley, PLOS One 2009).
A second group of patients in the study who, instead, received weekly
psychotherapy sessions and a placebo, had a smaller reduction in anxiety. Both
groups were encouraged to reduce their intake of stimulants (caffeine,
chocolate, tobacco, etc.) and were instructed in deep-breathing
exercises. A study among 60 men and women in India (average age 41)
with mild anxiety found that, compared to placebo, those who
took one capsule of standardized ashwagandha extract (Shoden,
by Arjuna Natural Ltd, which funded the study) daily for two months had a
greater average decrease in anxiety (- 4.2 points vs. - 2.5 points on a scale
from 0 to 56) as well as a significant decrease in average morning blood levels
of cortisol (the "stress hormone") (- 23% vs. no change for placebo).
Each capsule contained 240 mg of ashwagandha extract (providing 84 mg of withanolide glycosides) and was taken with a cup of water
after dinner. Testosterone did not increase in those who took ashwagandha,
although, interestingly, an earlier study with a lower dose of withanolide glycosides from the same brand of extract
reported a significant increase in testosterone in men (Lopresti, Medicine
2019).
A small study among people with generalized anxiety disorder, panic
disorder, and anxiety mixed with depression, found that those who took
ashwagandha extract (two to six 250 mg tablets per day, for a total daily dose
of 500 to 3,000 mg — amounts of withanolides not specified)
for 6 weeks had significant improvement compared to those taking a placebo (Andrade, Indian J Psychiatry 2000).
Stress
A study in India among 58 healthy men and women (average age 31) who reported
experiencing moderate levels of stress found that 300 mg of
the extract KSM-66 taken twice daily for two months resulted
in only slightly greater reductions than placebo in perceived stress (- 8.8 vs.
- 6 points on a scale of 0 to 40) and anxiety (- 4 points vs. - 2 points on a
scale from 0 to 56). The extract modestly decreased blood levels of cortisol (the
"stress hormone") compared to placebo (- 5.5 mcg/dL vs. 0.63 mcg/dL).
A lower dose of the extract (125 mg twice daily) did not decrease perceived
stress or anxiety compared to placebo (Salve, Cureus 2019).
However, a small,
company-funded study among 58 healthy men and women (average age 34) with
self-reported stress found that 400 mg of ashwagandha root and leaf extract
powder (NooGandha, by Specnova
LLC — amount of withanolides not provided) taken once
daily for one month did not reduce stress compared to placebo.
Supplementation also did not improve measures of cognition compared to placebo,
and there was no benefit with a lower daily dose (225 mg) of the same extract
compared to placebo (Remenapp, J Ayurveda Integr
Med 2021).
Insomnia
Clinical trials in India have shown that ashwagandha can reduce the
time needed to fall asleep, but only by about five to 10 minutes. One
study, among 58 men and women (average age 39) with insomnia, found
that 300 mg of ashwagandha root extract (providing at least 15 mg withanolides) twice daily for 10 weeks decreased the
average time to fall asleep by 12.62 minutes versus 8 minutes among those who
took a placebo. Although this improvement was significantly better for
ashwagandha than placebo, there was not a statistically significant difference
between the two in terms of increased time spent asleep (7.86 minutes for
ashwagandha versus 4.54 minutes for placebo) (Langade, Cureus 2019).
The extract used in the study, KSM-66 (Ixoreal Biomed
Inc), is in several products in this Review, although none were found to contain the expected amount of withanolides. A similar study among 73
people with or without insomnia (average age 37) found that taking this same
ashwagandha root extract at the same dosage for 8 weeks reduced the average
time to fall asleep in people with insomnia by about 14 to 15
minutes compared to only about 3 to 5 minutes among those with insomnia given
placebo. Ashwagandha also reduced the time needed to fall asleep in
people without insomnia, but only by about 3 minutes compared to placebo.
In addition, taking ashwagandha increased the time spent asleep compared
to placebo by about 37 minutes in people with insomnia and by about 9 minutes
in people without insomnia (Langade, J Ethnopharmacol 2020).
A study among 150 healthy men and women found that two capsules of a standardized
ashwagandha extract (providing a total 42 mg of withanolides
from 120 mg of the extract -- Shoden, by
Arjuna Natural Ltd, which funded the study) taken daily for six weeks improved
self-reported sleep quality by 72%, compared to an improvement of 29% among
those who took a placebo. However, more objective measures of sleep quality
(measured by a device worn on the wrist) showed only slight, but still
statistically significant, improvement: the time it took to fall asleep was 10
minutes with ashwagandha vs. 12 minutes with placebo. The two capsules were
taken with water approximately 2 hours before the evening meal (Deshpande, Sleep Med 2020).
Schizophrenia
A study among 66 men and women experiencing a worsening
of symptoms of schizophrenia found that those who took a standardized
ashwagandha extract (Sensoril, by Natreon Inc.) daily for three months had significant
reductions in negative symptoms (emotional flatness, lack of social drive,
etc.) and general symptoms (anxiety, depression, poor attention), although
there was no improvement in hallucinations, delusions, disorganized speech and
behavior, compared to placebo. Participants received 250 mg of ashwagandha
extract twice daily for the first week, after which the dosage was increased to
500 mg of extract twice daily (likely providing at least 100 mg of withanolides). Sleepiness, epigastric discomfort, and loose
stools were more common with the extract than with placebo (Chengappa, J Clin
Psychiatry 2018).
Male infertility, hormones and vitality
A placebo-controlled clinical study in men with low sperm count found one capsule
of ashwagandha extract taken three times daily (a total daily dose of 675 mg
extract, 33.75 mg withanolides) increased sperm
concentration, volume and motility by, respectively, 167%, 53% and 57% over 3
months. Compared to men who took a placebo, men who took the ashwagandha also
had a significant increase in serum testosterone levels (Ambiye, Evid Based
Complement Alterat Med 2013). A
14.7% increase in testosterone levels was also achieved in a study among
overweight men aged 40-70 years in Australia who were given ashwagandha for 8
weeks and placebo during a different 8 weeks. However, there we no significant
differences between the groups on symptoms of sexual well-being, vigor, fatigue
or levels of cortisol or estradiol. The ashwagandha was taken daily as two 300
mg tablets (taken 2 hours from a meal) providing a total of 21 mg of withanolide glycosides. The tablets were made from an
ashwagandha extract (Shoden® beads, Arjuna Natural
Ltd. — which funded the study but was not otherwise involved) (Lopresti, Am J Men Health 2019).
Sexual function in women
A 2-month study in 50 women ages 21 to 50 in India with low sexual desire
and/or arousal found those who took 300 mg of ashwagandha extract after eating,
twice per day, had significant improvements in overall sexual function,
including arousal, lubrication, and satisfaction compared to placebo; although
there was not a significant improvement in sexual desire. No adverse effects
were observed (Dongre Biomed Res Int
2015). The researcher's theorized that ashwagandha may
improve sexual function in women by reducing stress and potentially increasing
testosterone levels (as has been shown in men), although this was not measured
in the study. The extract used was KSM-66 from Ixoreal Biomed,
containing 5% withanolides, which is about 2 to 3
times as concentrated as the products in this Review. (Products containing this
extract were tested in this Review, however, they did not pass CL's testing, as
they contained lower than expected amounts of withanolides).
Hot Flashes and other symptoms of perimenopause
A study in India among 91 perimenopausal women (average age 47) found that 300
mg of ashwagandha root extract (KSM-66, as discussed above) taken twice daily
(providing a total daily dose of 600 mg containing 30 mg of withanolides)
for 8 weeks slightly reduced total symptom severity scores
(average decrease of 3.37 points vs. a decrease of 1.16 points with placebo on
a 44-point scale) based on symptoms such as mood, vaginal dryness, urinary
frequency, sweating and heart palpitations. Participants who took ashwagandha
also had, on average, one less hot flash per day than those who took a placebo.
In addition, blood levels of estradiol increased and levels of follicular
stimulating hormone (FSH) decreased in those who took ashwagandha compared to
placebo. There was no significant change in blood levels of testosterone (Gopal,
J Obstet Gynaecol Res 2021).
Thyroid function
A study in India found that ashwagandha improved thyroid function in men and
women with subclinical hypothyroidism, defined as mildly to
moderately elevated TSH levels (4.5 — 10 mIU/L) and
normal levels of T3 and T4. Compared to placebo, those who took 300 mg of
highly concentrated ashwagandha root extract (standardized to 5% withanolides) twice daily (total daily dose of 600 mg
extract containing 30 mg of withanolides) for two
months had an average decrease in TSH of 1.85 mIU/L
and increases in T3 and T4 averaging 0.5 nmol/L and 18.8 nmol/L, respectively.
(Sharma, J Altern Complement Med 2017). (The
extract was KSM-66 from Ixoreal
Biomed; see "Sexual Function in Women" above for products that
contain this extract.)
There is also evidence that ashwagandha may increase the effects of thyroid
medications, and may affect thyroid hormone levels even in people without
thyroid disease (See Concerns and Cautions).
Cognitive performance
Small but well-controlled studies in India have shown ashwagandha to improve
cognitive performance in adults. A study among healthy men found that taking
two 250 mg capsules of ashwagandha extract with a glass of water each morning
and evening (providing a total daily dose of 1,000 mg ashwagandha extract
[SENSORIL, Natreon, USA] with at least 100 mg of withanolides) for 12 days significantly improved cognitive
performance and reaction times compared to placebo (Pingali, Pharmacognosy
Res 2014). A study among men and women with mild cognitive
impairment (average age of 50) found that taking 300 mg of ashwagandha root
extract (KSM-66 from Ixoreal Biomed, USA) twice daily
(providing a total daily dose of 600 mg containing 30 mg of withanolides)
for 8 weeks significantly improved many aspects of immediate and general memory,
executive function, sustained attention, and information processing speed
compared to placebo (which showed lesser improvements). Most improvements were
not significant relative to placebo after 4 weeks and required 8 weeks. There
was no significant effect on visuospatial processing, i.e., drawing images from
memory and comparing rotated images (Choudhary, J Diet Supp, 2017).
Physical performance
A small study in healthy men and women ages 18 to 25 found that a daily dose of
500 mg of ashwagandha root extract (% withanolides
not listed) taken one hour after a meal for 2 months significantly improved
measures of physical performance and cardiovascular endurance, including
velocity while sprinting, leg muscle strength, and VO2Max (a measure of aerobic capacity) compared
to placebo (Sandhu, Int J Ayurveda Res, 2010). Similarly, a study of 38 recreationally active young men
who began a resistance exercise program four days per week and took 500 mg of a
standardized aqueous extract of ashwagandha roots and leaves with cold water
every morning for three months increased upper and lower body strength compared
to the same exercise regimen plus placebo. The extract, Sensoril (from Natreon,
which funded the study), has a particularly high concentration of withanolides (no less than 10%) — providing at least 50 mg
of withanolide glycosides per day (Ziegenfuss, Nutrients 2018).
A study in India among 50 healthy, athletic men and women
(average age 29) found that 300 mg of ashwagandha root extract (standardized to
provide at least 15 mg of withanolides) taken twice
daily for two months modestly improved cardiorespiratory endurance (as measured
by VO2 max) during a
12-minute run test compared to placebo. Those who took ashwagandha also
reported modest improvements in exercise recovery (e.g., perceived exertion and
fatigue) and reduced perceived general stress compared to placebo. The
manufacturer of the extract used in the study (KSM-66, Ixoreal Biomed Inc), provided the extract used in the
study, but did not fund the study. This extract is in several products in this
Review, although ConsumerLab found none contained the expected amount of withanolides based
on USP test methods (Tiwari, J Ethnopharmacol
2021).
Anti-inflammatory
Ashwagandha may have anti-inflammatory and analgesic properties. This was
demonstrated in a small but well-controlled study in India that also used Sensoril. In the study, people with joint pain and
discomfort from knee osteoarthritis took capsules containing 250 mg of extract,
150 mg of extract, or a placebo twice a day for 12 weeks. Significant
reductions were observed on measures of pain, stiffness, and disability at both
doses, although the 250 mg group showed earliest efficacy — at just 4 weeks.
There were no adverse effects reported and no one dropped out of the study,
although side effects were most common in the 250 mg group -- 20% of whom
reported nausea. (Ramakanth, J Aruv Integ Med 2016)
[The higher dose (250 mg) of extract used in this study would provide at least
50 mg of withanolides.]
Another clinical study found that two capsules (each containing 450 mg of
ashwagandha root, 50 mg zinc complex, 100 mg of guggul and 50 mg of turmeric)
taken 3 times daily for three months significantly reduced pain among patients
with osteoarthritis, but no improvements were seen on x-ray (Kulkarni, J Ethnopharmacol 1991).
Because the product contained a number of ingredients, it's not possible to
know what the effect of ashwagandha alone might have been.
Quality Concerns and
Tests Performed:
In
2014, only 2 out of 8 ashwagandha supplements selected for review by ConsumerLab passed testing, indicating a major problem with
quality in this category. Neither the Food and Drug Administration (FDA) nor
any other federal or state agency routinely tests ashwagandha supplements for
quality prior to sale. In order to help consumers
identify products of better quality, ConsumerLab.com once again purchased and
tested ashwagandha supplements to determine whether they contained the labeled
and expected amounts of withanolides and withanosides (referred to collectively in this report as withanolides). Products containing whole herbs or 250
mg minerals were tested to determine if they exceeded contamination limits for
lead, cadmium, and arsenic. All products in regular tablet/caplet form
underwent disintegration testing to check if they would break apart properly in
solution. ConsumerLab.com also determined whether the label recommended dose
provided at least 6 mg of withanolides.
See How Products Were Evaluated for
more information on testing.
What CL Found:
Only five, or 56%, of the nine ashwagandha supplements selected
for review by ConsumerLab passed testing and were
Approved for Quality. An additional six products were Approved that were tested
through ConsumerLab's voluntary Quality Certification Program.
Among all the products, the amount of withanolides
per daily serving (which should be 6 mg or more) ranged from just 0.57 mg to
95.3 mg. All products made with root powder were checked for heavy metals and
passed that testing and all tablets were able to properly disintegrate.
The reasons for the four products failing to
be Approved are explained below. It's important to note that each of these, as
well as two others that were Approved, also provided less than 6 mg of withanolides within their suggested daily serving:
·
Jarrow Formulas Ashwagandha provided only 0.57
mg to 1.1 mg of withanolides per suggested serving of
1 to 2 capsules daily, which was just 12.7% of the bare minimum expected — and
this was a lenient minimum based on an industry standard of just 1.5% withanolides. The USP minimum is higher — 2.5% and,
furthermore, the minimum for KSM-66 extract, the form claimed on the label, is
5% according the website of Ixoreal
Biomed, the company that sells KSM-66. Based on an expectation of 5% withanolides, each capsule should have provided at least 15
mg of withanolides — many times the 0.57 mg found in
testing.
·
Life Extension Optimized Ashwagandha Extract provided only 3 mg
of withanolides per suggested serving of two capsules
daily. It claimed to provide 25 mg of withanolide
glycoside conjugates (i.e., withanolides with
attached sugar molecules, also known as withanosides),
yet provided only 1.6 mg of this subset of withanolides
— only 6.3% of the expected amount.
·
ProHealth Optimized Ashwagandha provided 5.1 mg to
10.3 mg of withanolides per suggested serving of 1 to
2 capsules daily. Although, at two capsules, this is a reasonable daily dose of
withanolides, the amount found was only 85.6% of the
expected minimum based on the amount (400 mg per capsule). This product,
like Jarrow above, claimed to be
made with KSM-66 extract which is supposed to be 5% withanolides
and, therefore, each capsule should have contained 20 mg of withanolides
rather than the 5.1 mg found.
·
Himalaya Ashwagandha provided only 3.3 mg of withanolides per suggested serving of 1 caplet daily.
Although this was above the 3 mg total that it claimed to provide, it was below
the 4.4 mg one would expect as a minimum based on the amounts of root powder
and extracts listed. According to the USP, root powders should provide at least
0.3 withanolides, and the basic industry standard for
extracts is 1.5% withanolides, but Himalaya lists its
root powder at just 0.2% withanolides and its main
primary root extract at only 0.5% withanolides.
NOTE: ConsumerLab tested the extracts
in this Review using the official, validated USP (United States Pharmacopeia)
method, which covers extracts prepared using methanol, alcohol, water, or
mixtures of these solvents. The company that sells KSM-66 (Ixoreal
Biomed) claims that the USP method is not appropriate for testing KSM-66. In
correspondence with ConsumerLab, it claims that
KSM-66 is "a full-spectrum water-based extract" that contains a
"different set of withanolides and in higher
quantities than other extracts of ashwagandha and USP is still in the process
of updating its monograph to treat such extracts and compiling the
corresponding standards." Ixoreal Biomed's own method analyzes for withanolides
numbered 1 through 6, but it is unclear what these compounds are or how they
differ from those covered in the USP method. However, due to this
uncertainty, ConsumerLab has currently
assigned a status of "Uncertain" rather than "Not Approved"
to products that contain KSM-66 (Jarrow and ProHealth)
and those containing another unique water-based extract, Sensoril, (in Life Extension).
Although the following two products provided the amounts of withanolides
expected from their labels and were Approved for Quality by ConsumerLab,
be aware that they could potentially provide less than 6 mg of withanolides per day (the minimum amount typically in
ashwagandha used in clinical trials):
·
Pure Encapsulations Daily Stress Formula provided 7.7 mg of withanolides per suggested daily serving of 3 capsules;
however, its label promises only 5 mg and, therefore, it could potentially
provide less than 6 mg. It is a combination product that includes many other
ingredients used for stress or anxiety reduction such as L-tyrosine, rhodiola,
chamomile and lemon balm.
·
plnt by V [Vitamin
Shoppe] Ashwagandha suggests a serving of 1 to 3 capsules
daily and, at the top dose of 3 capsules it provides 7.2 mg, which is a
reasonable dose (although slightly below the 7.7 mg expected by ConsumerLab but within acceptable deviation). However, the
lower doses of only 1 or 2 capsules provide, respectively, only 2.4 or 4.8 mg
of withanolides.
Top Pick:
(Update 5/21/19) When this Review was initially published in
2018, Nature's Way Ashwagandha was our Top Pick among
the 11 Approved products. It provided the largest dose of withanolides
(up to 95.3 mg if taking 3 capsules, as shown in the graph above) at the lowest
cost per withanolides as shown in the graph below.
However, a scientific abstract published in May, 2019 indicated that there have
scattered reports of liver
injury associated with use of ashwagandha supplements,
including one case in 2016 in the U.S. involving Nature's Way
Ashwagandha. Although this is just a single report from several years ago
and other reports in Iceland involved a different brand (not covered in this
Review), considering the particularly high strength of the Nature's Way product,
we have decided to change our Top Pick to one providing a
significant but more conventional dose of withanolides
at a good price: GNC Herbal Plus Ashwagandha Extract (7 mg per
1 capsule daily for 13 cents).
Other good and well-priced options are the two following brands, although
neither appears to be currently available at this time: Sundown
Naturals Stress Support (37.6 mg per 3 capsules daily for 67 cents)
and Vitamin World Ashwagandha Extract (15 mg per 2 capsules
for 30 cents). We calculated that 6 mg of withanolides
costs about 11 to 12 cents from any of these three products, which is half the
price or better than from most other products. In fact, due to the unexpectedly
low amount of withanolides found in Jarrow, the cost to get 6 mg of withanolides
from that product was well over $1.
Test Results by Product:
Listed
below are the test results for 15 ashwagandha supplements. Nine products were
selected by ConsumerLab.com and six (each denoted with a CL flask) are included
for having passed the same evaluation through ConsumerLab's
voluntary Quality Certification Program.
Also listed is a product that was not tested but is very similar to one of the
Approved products.
Shown in the table are the claimed amounts of ashwagandha root power or
extract, serving sizes listed on the product labels, and amounts of total withanolides (including withanosides)
found. Products listed as "Approved" met contained the amounts of withanolides expected by ConsumerLab
from their listed ingredients and ConsumerLab.com's
other criteria for quality (see Passing Score). The full list of ingredients
is available for each product by clicking on the word "Ingredients"
in the first column, although some notable features are listed in the last
column, as well as price and cost comparisons.
|
RESULTS OF CONSUMERLAB.COM TESTING OF ASHWAGANDHA SUPPLEMENTS |
||||||
|
Product Name, Listed
Amount of Ashwagandha per Unit, Serving Size, and Suggested Daily Serving on
Label |
Claimed Amount and
Form of Ashwagandha Per Labeled Daily Serving |
—TEST RESULTS— |
Cost For Daily
Suggested Serving On Label |
|||
|
OVERALL RESULTS: |
Contained Labeled
Amount or Expected Amount of Withanolides
(Includes Withanosides) |
Did Not Exceed
Contamination Limits for Lead, Cadmium and Arsenic2 |
Disinte-grated Properly |
|||
|
Extracts: |
||||||
|
|
470 mg extract |
APPROVED |
|
NA |
NA |
$0.13 |
|
|
300 mg to 600 mg
KSM-66® extract |
UNCERTAIN |
Withanolides: 0.57 mg to 1.1 mg (12.7% of expected minimum) |
NA |
NA |
$0.12-$0.24 |
|
|
250 mg Sensoril® extract (root + leaf) |
UNCERTAIN |
Withanolides: 3.0 mg |
NA |
NA |
$0.23 |
|
|
600 mg to 1,200 mg
extract |
APPROVED |
|
NA |
NA |
$0.60-$1.20 |
|
|
1,000 mg 1,500 mg
extract |
APPROVED |
|
NA |
NA |
$0.45-$0.67 |
|
|
400 mg to 800 mg
KSM-66® extract |
UNCERTAIN |
Withanolides: 5.1 mg to 10.3 mg (85.6% of expected minimum) |
NA |
NA |
$0.21-$0.42 |
|
|
200 mg extract |
APPROVED |
|
NA |
NA |
$0.89 |
|
|
470 mg extract |
APPROVED |
|
NA |
NA |
$0.23 |
|
|
2,250 mg extract |
APPROVED |
|
NA |
NA |
$0.67 |
|
|
1,000 mg extract |
APPROVED |
|
NA |
NA |
$0.30 |
|
Similar to Approved Extracts*: |
||||||
|
Puritan's Pride® Ashwagandha (500 mg extract
per capsule; 1 capsule, twice daily) |
Similar to Vitamin
World® Ashwagandha Extract. |
$0.40 |
||||
|
Root Powders: |
||||||
|
|
1,600 mg root powder |
APPROVED |
|
|
NA |
$0.73 |
|
Combinations (Extract + Root Powder): |
||||||
|
|
380 mg organic root
powder |
NOT |
Withanolides: 3.3 mg (61.1% of expected minimum) |
|
|
$0.16 |
|
|
380 mg to 1,140 mg
root powder |
APPROVED |
|
|
NA |
$0.15-$0.45 |
|
|
100 mg to 200 mg root
powder |
APPROVED |
|
|
NA |
$0.22-$0.44 |
|
|
1,000 mg root powder |
APPROVED |
|
|
|
$0.17 |
|
|
||||||
|
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. |
||||||
|
Copyright ConsumerLab.com, LLC, 2018. All rights reserved.
Not to be reproduced, excerpted, or cited in any fashion without the express
written permission of ConsumerLab.com LLC. |
||||||
ConsumerTips™:
Choose
an ashwagandha supplement that lists its amount of withanolides
(either as a percentage of the amount of ashwagandha or a milligram amount).
Products made from root powder should contain a minimum of
0.3% (wt/wt) total withanolides and extracts should contain
at least 1.5% (wt/wt) total
withanolides, in fact, the United States Pharmacopeia
requires no less than 2.5%, and some proprietary extracts, such as KSM-66,
claim to be 5%. Look for products which provide a minimum of 6 mg of withanolides when taken at the number of servings suggested
on the label.
Dosage:
Daily doses between 1,000 mg and 6,000 mg of ashwagandha root powder and
from 500 mg to 1,500 mg of extract have typically been used in
clinical studies. See the What It Does section for dosage details
for specific medical uses.
Concerns and Cautions:
Ashwagandha
is generally well tolerated. However, mild to moderate side effects including headache,
sleepiness, nausea, gastrointestinal upset, vomiting, or diarrhea have
been reported in some clinical studies (Ramakanth J Ayurveda Integr Med 2016; Chengappa, J Clin
Psychiatry 2018).
Ashwagandha (Withania somnifera)
is part of the Solanaceae family of plants, also known as
"nightshades." In people who are allergic to other nightshade
plants such as potato, eggplant, tomatoes and peppers, ashwagandha
could potentially cause allergic reactions such as rash, itching,
nausea, wheezing or difficulty breathing.
Burning, itching, and discoloration of the skin of the penis was
reported in a man who took 5 grams of ashwagandha root powder for six days.
Symptoms resolved when he stopped taking ashwagandha (although some skin
discoloration remained), but returned when took ashwagandha again, suggesting
what is known as a "fixed drug eruption" — when repeat exposure to a
substance results in a new skin lesion as the same location that was previously
affected — commonly the lips, hands, and genitalia (Sehgal, Skinmed 2012).
Some preliminary research suggests ashwagandha could potentially lower
blood pressure. It should be used with caution in people with low blood
pressure and in those taking medications to lower blood pressure, as it may
enhance the effect of these medications. It may also have sedating effects, and
should not be used with other herbs or medications that cause sedation, or
prior to receiving anesthesia.
Ashwagandha may lower blood sugar levels; it should not be used by
people with diabetes or hypoglycemia except under physician supervision (Andallu, Indian J Exp Biol 2000).
Ashwagandha should be used with caution in people with hyperthyroidism and
people taking thyroid hormones, as it may increase the effects of these
medications. Animal studies and a small study in people suggest ashwagandha may
increase thyroid hormone levels (Panda, J Pharm Pharmacol 1998; Gannon, J Ayurveda Integr Med
2014), and there are case reports of ashwagandha causing
thyrotoxicosis (hyperthyroidism) in people not previously diagnosed with
thyroid disease, such as in a healthy woman in the Netherlands taking
ashwagandha capsules for several weeks or more (van der Hooft, Ned Tijdschr Geneeskd 2005). Similarly, a healthy 62-year-old
woman in the U.S. developed thyrotoxicosis after taking an ashwagandha
supplement (Physician's Choice Extra Strength Ashwagandha capsules -- 1,950
mg ashwagandha root + 15 mg black pepper extract) daily for two months. She
experienced trouble swallowing due to thyroid enlargement as well as anxiety
and emotional outbursts, confusion, weight loss, weakness, increased resting
heart rate, and became mildly anemic (which can occur with thyrotoxicosis).
Approximately one month after stopping ashwagandha supplementation and
receiving medical treatment, her thyroid hormone levels normalized, her
symptoms improved, and she was no longer anemic (Curry, SSRN 2019).
It's possible that ashwagandha could affect heart rhythm in
some people. Dizziness, rapid heartbeat (ventricular tachycardia) and fainting
associated with the use of ashwagandha have been reported in two middle-aged
men in India; however, no information about the source, brand or dose of
ashwagandha was provided (Dwivedi, Trop Doct
2011).
Animal studies suggest that ashwagandha may
stimulate the immune system and, therefore, could potentially decrease the
effects of immunosuppressant drugs such as cyclophosphamide
(Cytoxan, Neosar) and tacrolimus (Envarsus
XR, Protopic, Prograf),
and/ or trigger organ rejection in organ transplant recipients (Davis, J Ethnopharmacol 1998; Davis, Cancer Lett 2000). This was
reported in a 69-year-old kidney transplant recipient in Canada who had been
stable for two years after transplant while taking the immunosuppressants
tacrolimus, mycophenolate sodium (Myfortic) and
prednisone (Deltasone), but developed acute organ rejection that required
removal of the kidney two weeks after he began taking two ashwagandha pills
daily (brand and dose not provided) (Sriperumbuduri, Kidney
Int Rep 2020).
Preliminary laboratory and animal studies suggest ashwagandha
may have a blood-thinning effect. Until more is known, it should be used with
caution in people taking blood-thinning medications such as
aspirin, warfarin (Coumadin) or heparin, anti-platelet drugs such as
clopidogrel (Plavix) (Ku, Vascul
Pharmacol 2014; Madhusudan, Pharm Biol 2016).
There is some concern that ashwagandha could increase the
risk of miscarriage in pregnant women; women who are pregnant or
nursing should not take this herb.
Although rare, cases of elevated liver enzymes and
liver injury have been reported with use of ashwagandha supplements.
Three cases were reported in Iceland between 2017 and 2018 with NOW brand
ashwagandha (450 to 1,350 mg of extract daily) and two cases were reported in
the U.S. in 2016 (one product was identified as Nature's Way brand
— Note: Nature's Way Ashwagandha was tested by CL for
this Review in 2018. It was Approved and was notable for
containing the highest amount of withanolides per
capsule among the tested products). In these cases, symptoms including nausea,
lethargy, itching, abdominal discomfort and jaundice occurred two to 12 weeks
after beginning supplementation (daily dosage ranged from 450 mg to 1,350 mg
from supplement brands NOW and Nature's Way) and
resolved within one to six months after stopping supplementation. None of the
cases resulted in liver failure (Bjornsson, Abstract in Gastroenterology
2019). In another case, a 40-year-old man developed
itching and jaundice, with a rise in liver enzymes and bilirubin in the blood,
twenty days after beginning supplementation with Now brand
ashwagandha (Ashwagandha Now, 450 mg per day). In the year prior to
taking Now, the man had taken 500 mg daily of another brand of
ashwagandha without any indication of liver injury and had no history of liver
disease (Weber, Am J Gastroenterol 2021). Until
more is known and long-term safety studies are conducted, ashwagandha should
not be used by people with kidney or liver disease. Also be aware
that, as described above, cases have been reported in people without a
history of liver disease.
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 Ashwagandha
11/30/2021
Does ashwagandha
supplementation reduce stress? See what a new study found in the What It Does section of our Ashwagandha
Supplements Review.
11/02/2021
Can ashwagandha
supplementation reduce hot flashes and other symptoms of perimenopause? See
what a new study found in the What It Does section of our Ashwagandha
Supplements Review. Also see our Top Picks for ashwagandha.
7/10/2021
Although rare, liver
injury has been linked to the use of certain ashwagandha supplements. Another
case was recently reported. Get the details in the Concerns and Cautions section of the
Ashwagandha Supplements Review.
Ashwagandha for Exercise Endurance?
3/06/2021
Can ashwagandha improve
endurance and decrease fatigue during exercise? See what a new study found in
the What It Does section of the Ashwagandha
Supplements Review. Also see our Top Pick among ashwagandha supplements.
1/03/2021
Ashwagandha may decrease
the effectiveness of immunosuppressant drugs and, according to a recent case
report, may trigger transplant rejection. Get the details in the Concerns and Cautions section
of the Ashwagandha Supplements Review. The section includes information about
other potential side effects of ashwagandha.
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