It’s also known as the winter cherry and poison gooseberry. It’s not poisonous though, as that moniker probably came from its taste and smell.
In India’s native language, it translates as “the smell of the horse.” Many sources claim the origin of the name is because it provides the strength of a horse. Perhaps, but more likely is because this root literally smells like a horse.
Fortunately though, this horse-smelling root is not used as food, but rather in powder form as a supplement. Ayurvedic medicine has reportedly used it as such for thousands of years.
What’s found above the ground – the reddish orange fruit – can be used as food. It’s in the same family as the tomato, but only about the size of a marble. Other than as a rennet for cheese production, the berries are rarely eaten in their native growing regions of India, China, Nepal, and Yemen.In India, historically a more common use of the berries and leaves were for ulcers and protruding tumors. The plant would be applied on the skin above as an Ayurvedic treatment.
In Yemen, they also make use of the leaves. For burns and other cuts, they use a powdered form as an herbal treatment called ubab.
While there is some scientific research on the leaves, the vast majority revolves around ashwagandha root extract. As an herbal remedy, it is the root of the plant which has been associated with a plethora of health benefits. Now, Western medicine is trying to figure out if they’re for real or not.
Is the hype justified?
Lately, there has been quite a bit of buzz specifically about ashwagandha for men. Yes, it is true there has been a fair number of studies investigating it as a testosterone booster, enhancer of sperm quality, and erectile dysfunction remedy, among others.
However setting those aside, all of the other suggested health advantages may equally influence women, too. In fact, there are a couple unique to females.
Similar to Netflix’s Stranger Things, there seems to be a lot of bizarre stuff going on with this root, and just like in the show, no one is able to fully explain it. Despite the dozens of clinical studies, researchers are able to suggest what it might be doing, but they seem to have no clue as to why exactly it’s happening.
Nor can they say why men seem to get more muscle strength by using it.
Let’s review both the gender specific and shared perks which have been proposed so far, like anti-anxiety and weight loss (and hey, less stress does often equal less eating). Though keep in mind none of the suspected uses have enough studies behind them to be claimed as certain or proven, therefore please keep in mind that all of the following have only been suggested as possibilities.
Beginning with the ladies first…
We see this often claimed as an advantage, but there’s only one clinical study which looked at menopause symptoms and it had some major design flaws.
A randomized open clinical trial was conducted in India involving 51 women who were going through menopause (1). Their ages ranged from 40 to 55. Each received the following Ayurvedic treatments:
- Ashwagandha churna – 3,000 mg (3 g) dose taken with milk a half-hour before food, twice daily
- Ashokarishta – 25 ml mixed with an equal quantity of water, taken after food twice daily
- Praval pishti – 250 mg capsule taken with milk, twice daily
All 51 of the women received this daily combination and were followed for one month. A number of side effects were measured including hot flashes, sleep problems, depression, irritability, anxiety, vaginal dryness, stamina, and a few others. Overall, the results after one month of using the treatment:
- 2 women were unchanged (3.92%)
- 40 women “mildly improved” (78.43%)
- 9 woman “moderately improved” (17.65%)
- None experienced “complete improvement”
Interesting findings, but keep in mind that:
- 3 herbal remedies were given at the once, so it’s not helpful in evaluating the effects of ashwagandha root separately.
- There was no placebo/untreated group used for comparison.
- This was an open trial, where the patients knew what they were receiving. It’s likely some experienced improvement because they believed it would help… not because it actually worked on them (or worked as well as they believed).
The ability to boost female libido has been claimed by many for this root, but until recently the “evidence” to support was only indirectly related at best:
- Stress as cause – One source we saw cited a study from 1993 about stress being a cause of infertility, yet it had absolutely nothing to do with ashwagandha (2).
- Anti-anxiety and antidepressant – Another claimed a study which looked at these characteristics in rats – not humans – was somehow proof that Indian ginseng could help boost female libido, even though that study mentioned nothing related to sexual activity (3).
- Thyroid hormones – This was the most laughable. Claiming that ashwagandha root extract boosting thyroid hormone concentrations in male mice somehow helps female humans and their libido (4)
Those are grasping at straws. Finally in 2015 there was actually a relevant study published (5): “Efficacy and Safety of Ashwagandha (Withania somnifera) Root Extract in Improving Sexual Function in Women: A Pilot Study.”
- 50 women were selected, ranging from 21 to 50 years of age.
- All were in a relationship with a man currently and had been in that same relationship for at least one year.
- They were randomized to receive either a placebo or 300 mg of ashwagandha to take twice daily.
- Treatment period was 8 weeks.
To gauge effectiveness, the Female Sexual Function Index (FSFI) and the Female Sexual Distress Scale (FSDS) questionnaires were given before and after.
Not a single woman in the treated group reported any adverse side effects. The root extract scored higher versus placebo for all of the traits measured; desire, lubrication, orgasm, arousal, and satisfaction. The latter two showed the greatest increase over placebo:
While those charts may seem impressive, it’s important to remember this is only one small study where 25 women received the extract and 25 received placebo. This study does suggest an advantage may exist, but clearly we need more medical reviews for ashwagandha and female libido before drawing any conclusions.
What happens with men…
As a man, obviously you don’t want to increase estrogen or use something that has the same effect, like sources of phytoestrogens. Some have said that ashwagandha is an estrogen blocker but there’s no evidence of that. However what it might do, at least in men, is increase natural testosterone production.
While it certainly is far from proven, the good news is that we have at least 4 different studies involving male humans, where testosterone levels were measured before/during/after supplementation. However all of these looked at men in specific circumstances. None looked at healthy average men who did not have fertility problems or weren’t bodybuilding.
Bench press and leg extension study
Published in 2015, a randomized double-blind and placebo-controlled clinical study sought to find out if ashwagandha would help muscle strength and gain (those suspected perks will be discussed below) (6).
A total of 50 young to middle aged men participated (18 to 50 years old) and out of those 25 received placebo and 25 received 300 mg of the root extract twice daily.
“…significantly greater increase in testosterone level” for the group taking the herb, as seen in the graph. At the start, as you see they actually had less testosterone to begin with versus placebo.
There were 3 similar studies conducted in India:
- A 2013 study involved 180 men who had fertility problems. They were given 5 grams per day of the Withania somnifera root powder for a period of 3 months (7).
- A 2010 study involving 75 healthy men (control group) and 75 who were undergoing fertility screening. The latter received 5 grams per day (with milk) (8).
- A 2009 study looked at stress-related male fertility problems. A total of 60 men participated; 20 were heavy smokers, 20 were under psychological stress, and 20 were normozoospermic (had normal sperm) but still dealt with infertility. All received 5 grams per day for 3 months (9).
Although testosterone was not the primary focus, the levels were found to be higher post treatment in all 3 studies. The diagram here is from the 2009 study, showing the theory of why and how ashwagandha works.
Only one study from 2011 looked specifically at this issue. There were 86 men total; 41 received a 6 gram daily dosage of ashwagandha while 45 received a placebo for their ED (10).
The root extract did not help. In fact, the treated group had a lower rate of improvement versus placebo.
The researchers proposed different reasons why, such as that many were severely affected men who came to Ayurvedic medicine as a last ditch effort after failing with traditional treatments. Whatever the case, there are no studies which suggest this herb can help erectile dysfunction.
Sperm count and quality
These traits – not testosterone – were the focus of the 3 male fertility studies mentioned above.
The 2013 study
This was the largest, as it involved 180 infertile male patients, plus another 50 healthy males who were used as a control group. Their ages ranged from 22 to 45.
Of the 180 in the treatment group, there were subgroups:
- 60 normozoospermic – normal semen profiles, unknown cause of infertility
- 60 oligozoospermic – men with low sperm count
- 60 asthenozoospermic – men with reduced sperm motility
The researchers used high-resolution Nuclear Magnetic Resonance (NMR) spectroscopy to measure semen samples for the following amino acid levels:
- Glutamic acid (glutamate)
As well as the following compounds:
- Glycerophosphocholine (GPC)
They wanted to compare the levels of these in the infertile men versus those with healthy reproductive systems. It was inferred that lower/abnormal levels of these metabolites correlates with higher infertility.
It was concluded that the daily 5 gram ashwagandha supplement given for 3 months to the infertile men:
“…repairs the disturbed concentrations of lactate, alanine, citrate, GPC, histidine, and phenylalanine in seminal plasma and recovers the quality of semen…”
Sperm motility and concentration were said to increase in all 3 treated groups. The following was also observed:
- Testosterone and luteinizing hormone increased in all 3 groups
- Prolactin and follicle-stimulating hormone decreased in all 3 groups
Luteinizing hormone stimulates the production of testosterone and higher levels of both are believed to be beneficial in this situation. The decrease in prolactin levels is considered to be a good thing, too.
Follicle stimulating hormone (FSH) which was decreased is important for both women and men in their reproductive health. In males, it influences sperm production and healthy levels are thought to be between 5 and 15 IU/L.
Like almost any hormone, you don’t want FSH too high or too low. Low levels can indicate sperm is not being made and high levels can be a sign the testicles are not functioning right. Therefore, you can’t make a blanket statement and say lower FSH is good for you or bad for you… it really depends on where your starting point was (whether it was low or high to begin with) and the reason for it being there.
The 2010 study
This had a control group in addition to the treatment group; 75 men in each. All being 25 to 40 years old, they were relatively young.
Of the 75 in the treatment group, there were subgroups:
- 25 were normozoospermic (unknown cause for infertility)
- 25 were oligozoospermic (low sperm count)
- 25 were asthenozoospermic (low sperm motility)
Ashwagandha for the male infertility group was the same amount; 5 grams per day taken with milk, for a period of 3 months. Apparently they are using this dosage for fertility because it was previously discussed in the 1974 Ayurveda medical book Unani dravvyagunadarsh, Volume II.
Both before and after treatment, semen samples were collected to measure:
- Semen volume
- Sperm concentration
- Sperm count
- Sperm motility
Seminal plasma levels were also measured for the following, which were all said to be sub-optimal:
- Vitamin A, C, and E
- Corrected fructose
- Testosterone and luteinizing hormone – said to be too low before treatment
- Prolactin and follicle-stimulating hormone – said to be too high before treatment
It was said that sperm motility was “significantly improved in all groups” but the increase was “less than optimal” in the 25 men with low sperm motility (asthenozoospermic). It was also said “the change was not significant” in semen volume for that group, but it was significant for the other two (normozoospermic and oligozoospermic).
The root extract was said to recover levels of vitamins A, E, and C for all 3 groups versus their pre-treatment levels. Likewise for corrected seminal fructose.
The researchers suggested that the previously low levels of those vitamins caused reduced antioxidant capacity and that negatively correlated with the sperm concentration and motility. Or in a nutshell, healthier levels of those antioxidants correlated with healthier motility and volume.
As far as testosterone and the other hormones, it was claimed:
“Treatment with W. somnifera restored the level of all four hormones.”
The 2009 study
Unlike the other two, this study wanted to look at situations where the infertility might be caused by stress. Ashwagandha for stress relief has long been touted. For that reason, the researchers wanted to see if the suspected anti-stress qualities would help the 60 men in the study:
- 20 heavy smokers
- 20 under “psychological stress” according to the State-Trait Anxiety Inventory (STAI) (11)
- 20 with normal sperm but still had infertility
As in the others, the same 5 gram daily dosage was given for 3 months.
In all 3 groups, signs of oxidative stress improved in the seminal plasma:
- Decrease in signs of oxidative stress; lipid peroxide
- Increase in natural antioxidants created by the body; superoxide dismutase, catalase, glutathione
- Increase in dietary sources of antioxidants; ascorbic acid (vitamin C), vitamin A, vitamin E
As in the last study, the pattern of hormonal changes followed a similar pattern:
- Increase in luteinizing hormone and testosterone
- Decrease in prolactin and follicle-stimulating hormone
In addition, this study measured cortisol which is nicknamed “the stress hormone” and that too decreased. As far as the semen:
- Liquefaction time decreased (longer times were said to correlate with infertility)
- Volume increased
- Motility increased
- Sperm concentration increased
That covers the things which are gender specific. Now let’s review benefits which might help both genders. Sure, some might be of more interest to women or vice-versa, but they will be of interest to all to at least some degree.
Anxiety and stress
The translation of the Latin word “somnifera” in Withania somnifera means sleep inducing, as a calming effect has long been associated with this plant. However, conducting clinical trials to evaluate this have primarily taken place within just the past two decades.
Since adrenal stress can cause hypothyroid symptoms, it comes as no surprise that animal studies have suggested a possible ashwagandha thyroid link.
In fact, a medical paper from 2005 discussed a 32 year old Dutch lady who experienced thyrotoxicosis (excessive production of thyroid hormone) after using the root supplement (12). It was proposed that it might be because it stimulates production of thyroxine (T4) and triiodothyronine (T3), but so far no human clinical studies have focused on is effect on thyroid function.
The earliest study from 2000 was double-blind and placebo-controlled, but it was very small and 18 out of the 39 people dropped out before finishing (13). Because of these things it’s hard to place much weight on this study, but it was concluded that the 250 mg supplement taken twice daily improved symptoms for generalized anxiety disorder; 88.2% improvement versus 50% with placebo.
The Canadian postal worker study
This one may be more useful, as it followed 75 Canadian postal workers who had been diagnosed as having moderate to severe anxiety (14).
Roughly half were treated with standardized psychotherapy (PT group) while the other half received 300 mg of ashwagandha twice daily + dietary counseling + multi-vitamin + deep breathing relaxation lessons (NC group). The results according to the Beck Anxiety Inventory (BAI) questionnaire are shown below.
The group using the “Indian ginseng” did improve more, but given that other things like breathing techniques and dietary counseling were provided to them, it’s unknown how much – if any – was due to the root extract.
Adverse side effects for ashwagandha are noted as gastrointestinal upset, overstimulation, rash, feeling warm, increased frequency of night cramps, and mild hair loss. However with the exception of rash and feeling farm, their rate of occurrence was the same as in the placebo group.
|Side Effect||Ashwagandha Group||Placebo Group|
|Increased night cramps||1||1|
|Mild hair loss||1||1|
It’s unknown whether it’s statistically significant, but a small amount of weight loss for those using ashwagandha was seen, more so than in the psythotherapy group. Since they were overweight (28 average BMI) this was probably a good side effect, if it was caused by the root extract.
Chronically stressed study
64 men and women with a history of chronic stress were given a 300 mg ashwagandha extract dosage twice per day or a placebo (32 for each group) (15).
They were 18 to 54 years old and all quite healthy, since they excluded anyone who had diseases which were psychiatric, cardiovascular, respiratory, nervous system, endocrine, gastrointestinal, urinary, or genital related.
The supplementation was given for 60 days, at which time a final assessment was done and blood samples were taken to compare before and after.
According to the Perceived Stress Scale or PSS (which is frequently used in psychology) the placebo group improved 5.5% while the ashwagandha improved 44%.
Per the GHQ-28 questionnaire for general health, the results were:
- Somatic: 76.1% reduction for ashwagandha group vs. 4.9% for placebo
- Anxiety and insomnia: 69.7% for treated vs. 11.6% for placebo
- Social dysfunction: 68.1% for treated vs. -3.7% for placebo
- Severe depression: 79.2% for treated vs. -10.6 for placebo
The Depression Anxiety Stress Scale (DASS) followed a similar trend for its criteria.
Cortisol levels were measured and the treated group had a 27.9% reduction from baseline while placebo had a 7.9% reduction.
Is ashwagandha safe? There were 6 “adverse events” reported for the treated group; nasal congestion, reduced appetite, cough/cold, constipation, drowsiness. The placebo group reported a similar number – 5 adverse side effects – albeit different ones; sleepiness, gastrointestinal issues, fever, headache, dry mouth.
It was said that the side effects and differences between both groups was not statistically significant. The researchers seemed to infer that these results did not disprove the safety profile of this herbal supplement.
The conclusion stated:
“…high-concentration full-spectrum Ashwagandha root extract improves an individual’s resistance towards stress and thereby improves self-assessed quality of life.”
Endurance, muscle strength
Some of the most interesting, yet least discussed studies are those related to fitness uses. Not all specifically focused on these, but had findings which suggested them.
For example, a study from several years ago looking at safety had included 3 tests for muscle strength (among many other tests unrelated to fitness) (16). The increase in hand grip force was not statistically significant, but the increase in back extensor force and quadriceps force was.
There are a few studies though which specifically looked at physical endurance…
Untrained college students study
This involved 40 college students (22 males, 18 females) with an average age of 20.6 years (17). They were all healthy, but none had regularly gone to the gym during the past 6 months. In other words, they were looking at exercise performance and muscle strength using out of shape people.
500 mg gelatin capsules for the following were given:
- 10 participants got placebo
- 10 received ashwagandha root extract
- 10 received arjun tree bark extract (Terminalia arjuna)
- 10 received both extracts (250 mg of each)
Their physical ability was tested before and after using a number of methods:
- Scales – for measuring weight and BMI
- Kinematic Measuring System (KMS) – an instrument that measures speed using 4 difference cameras simultaneously, which was used to for the sprints and jumps
- Vista Turbo Trainer – to measure VO2 max
- Wobble board test – a 20 second procedure analyzed by software
- Blood pressure monitor – their normal resting rate was taken into account, too
For the combination of both herbs:
- VO2 max: 6.8% more improvement vs. placebo
- average absolute power: 11.3% more
- average relative power: 10.1% more
- maximum velocity: 1.8% more
- systolic blood pressure: 4.4% lower
For the group receiving the root dosage of 500 mg:
- VO2 max: 6.8% more
- average absolute power: 8.8% more
- average relative power: 10.1% more
- maximum velocity: 2.9% more
- systolic blood pressure: no significant change
After analyzing the differences between the 4 groups, the conclusion was that:
“Withania somnifera increased velocity, power and VO2 max whereas Terminalia arjuna increased VO2 max and lowered resting systolic blood pressure.”
Professional athlete study
Unlike the last one which looked at healthy but out of shape people, this study used “elite” Indian cyclists (18). They defined “elite” as athletes who had participated in state-level events. There were a total of 40 athletes (20 men, 20 women) and their average age was approximately 20 years old.
They were randomly divided into two groups. Half received a placebo while the other half received 500 mg of ashwagandha capsules. The supplements were given for 8 weeks.
Both before and after, treadmill tests were used to measure VO2 max, metabolic equivalent, respiratory exchange ratio (RER), and time until exhaustion.
The placebo group did not show any improvement, but there was “significant improvement” in the treated group. For males:
- 1% improvement in VO2 max
- 7% in time to exhaustion
- 8% for metabolic equivalent
- 8% for respiratory exchange ratio (RER)
- 0% improvement in VO2 max
- 7% in time to exhaustion
- 6% for metabolic equivalent
- 5% for respiratory exchange ratio (RER)
While it still appeared to be an advantage for women, clearly they experienced less improvement in all 4 parameters.
As to why the men benefited more from the ashwagandha supplement, it was proposed that it might have something to do with its effect on the endocrine system. They cited an earlier study involving mice which suggested that the root extract increased the males’ testicular weight (19).
This focused specifically on muscle growth and strength gain (20). Basically, it was for bodybuilding since the tests used were bench press and leg extensions. Creatine Kinase (CK) levels were measured for evaluating muscle recovery and injury. This study was mentioned above since testosterone levels were measured and found to be higher after supplementation.
The researchers recruited men that were 18 to 50 years old who had “little experience” when it came to resistance training. They were recruited using fliers at a gym.
A total of 50 men completed the 8 week study, during which half received placebo and half received 300 mg of the root extract twice daily.
Ashwagandha seemed to help muscle strength, mass, and recovery, as well as body composition:
- arm muscle size gains of 8.89 cm2 for the treated group vs. 5.30 cm2 for placebo
- chest muscle increase of 3.37 cm for treated vs. 1.43 cm for placebo
- thigh muscle increase of 8.71 cm2 vs. 6.22 cm2 for placebo
- muscle recovery was “substantially higher” in the ashwagandha group based on serum creatine kinase levels; 1462.68 U/L vs. 1307.48 U/L
- body fat percentage decrease was “significantly greater” in the ashwagandha group; -3.47% vs. -1.52%
The first was in 2000 and only involved 12 people; 6 with type 2 diabetes and 6 with high cholesterol. The results did seem to suggest it helped to lower LDL cholesterol and had anti-glycemic properties (23).
A randomized, double blind, placebo controlled pilot trial published in 2013 did suggest it lowered serum triglycerides and fasting blood glucose (blood sugar), but that only looked at hospital patients with schizophrenia, not the general population (24).
The following two studies are probably are the most useful.
The healthy young adults study
This one only had 17 participants, but at least they were all comparable; healthy volunteers between 20 and 27 years old, with an average BMI of 24. All were non-smokers and non-alcoholics (25).
How much ashwagandha they took was:
- 750 mg daily for days 1-10
- 1,000 mg daily for days 11-20
- 1,250 mg daily for days 21-30
The focus here was safety, not specifically cholesterol. Though among the many tests administered, they did measure HDL, LDL, VLDL, and total cholesterol.
The conclusion? The supplement was “well tolerated” and there was a “significant” reduction in total and LDL cholesterol (which is the “bad” kind you want lower). HDL or “good” cholesterol” remained unchanged.
The chronically stressed study
Previously discussed above, this study may be the most interesting even though cholesterol was not the focus. Why? Because it’s a bigger sample size (64 participants) and more than one Withania somnifera dosage was used.
At the end of the 60 days, the lipid profiles showed the following:
- 19 people received 125 mg once daily dose and experienced -6.4% in LDL, -8.9% in VLDL, and +2.9% in HDL cholesterol
- 30 received 125 mg twice daily experienced -9.0% in LDL, -16.6% in VLDL, and +4.6% in HDL cholesterol
- 34 received 250 mg twice daily and experienced -17.4% in LDL, -23.9% in VLDL, and + 17.3% in HDL cholesterol
- 15 received placebo and experienced -0.6% LDL, +8.5% VLDL, and -0.5% HDL cholesterol
The pattern suggests that it may assist with cholesterol and the amount of change appears to correlate with dosage.
There is even less evidence to suggest this, but given the popularity of diet supplements and interest in this topic, let’s review what research there is so far.
The Canadian postal worker study
The largest, since it involved 75 people. Here is how their weights compared before and at the end of the 12 week study:
- Weights dropped by 4.37 lbs (1.98 kg) in the treated group versus 1.12 lbs (0.51 kg) with placebo
- BMI decreased by 0.75 versus 0.19 with placebo
This was the study where the treated group received 300 mg of ashwagandha twice daily, in addition to a multi-vitamin, dietary counseling, and deep breathing lessons. One of those other factors may be responsible for the improvement.
The healthy young adults study
This only involved 17 participants who used the supplement for 30 days.
- body fat percentage showed a decrease from 27.78 to 25.51
- lean body weight actually increased from 105.20 lbs (47.72 kg) to 109.22 lbs (49.54 kg)
Given the short duration and small sample size, it’s hard to read much into this.
The bodybuilding study did show a drop in body fat percentage (-3.47% vs. -1.52% in placebo). However that involved intense strength training at the same time, something which is not relevant to most people. The benefits of ashwagandha for weight loss remain unproven and as you can see, there’s not much research in humans for this. Be wary of those who advertise it as a diet pill to lose belly fat or some other far out claim.
In addition to those discussed, there has also been preliminary research into the possibility of the root extract lowering blood sugar, reducing fatigue, helping with sleeping problems/insomnia, DHEA levels, depression, C-reactive protein, thyroid, and heart rate.
However as is the case with everything discussed so far, if you use this as a dietary supplement, please remember the health claims have not yet been proven. Much more human clinical research is needed. It should not be used for any disease.
How to take ashwagandha
Given the unappealing taste of the root extract, today most prefer to take this supplement in the capsule form. A typical dosage may be 1 to 3 times daily, taken with a potency of 250 or 300 mg per capsule. Rather than using capsules, the traditional Ayurvedic way is to make ashwagandha tea using the ground root powder and mixing it with warm milk and honey.
When is the best time to take it? Many use equal doses spread throughout the day, such as in the morning and evening if taken twice daily. For sleep quality or insomnia, some believe it’s best to take 30 minute before bed.
The following are not endorsements, but rather 3 supplements which have a high number of positive customer reviews:
- Organic India herbal supplement (90 capsules)
- NOW Foods extract 450 mg (90 VCaps)
- BRI Nutrition pure root powder 1,000 mg (90 count)
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.