Friday, February 12, 2010

Ashwagandha as a Nootropic – Experiment Begins

Ashwagandha, the 'Indian ginseng', shares some of the properties of Korean ginseng.
Ashwagandha, the 'Indian ginseng', shares some of the properties of Korean ginseng. (Photo by bartpogoda)

Ashwagandha is one of the plants used in Ayurvedic medicine. Also known as Indian ginseng, the scientific name of this nightshade family member is Withania somnifera. The latter part of the name means "sleep-inducing" in Latin, suggesting that the plant is used for its relaxing properties.

Ashwagandha is also said to be an adaptogen – a herb that increases the body's resistance to stress, anxiety and fatique by "normalizing" its functions. Before you dismiss the whole thing as new age garbage, let me point out that unlike some other Ayurvedic herbs, this one has been studied quite extensively. A pubmed search on 'ashwagandha' gives about 360 results.

Having browsed through the entire list, it appears that ashwagandha has a variety of effects on health. In this post, however, I will concentrate on the nootropic aspect of the herb. Bear in mind that I'm using the term in a very broad sense here: any paper examining the effect of the herb on cognition, mood, stress-relief, or motivation will be included. We'll save the studies on topics such as immune function for later.

The effect of ashwagandha on mood and libido

GABA, which is short for gamma-Aminobutyric acid, is the chief inhibitory neurotransmitter in mammals. GABA agonists – drugs that stimulate or increase the action at the GABA receptor – usually have a relaxing and stress-relieving effect. Alcohol is one such agonist. At least one paper has shown that ashwagandha contains an ingredient that activates the GABA receptor in a dose-dependent manner (link). Thus, the GABAergic activity may explain why many people report feeling more relaxed after taking ashwagandha.

GABA agonists are sometimes also used to treat psychostimulant addiction. Indeed, in animal models of drug addiction, ashwagandha apparently reduces alcohol intake and morphine tolerance (link). Ashwagandha itself appears to be well-tolerated: a review concluded that it has little or no risk of toxicity (link).

In a study that examined the role of stress in male infertility, 5 grams of ashwagandha root powder was given daily for 3 months to infertile men suffering from psychological stress (link). The treatment resulted in a decrease in stress levels and an increase in the level of antioxidants. At the same time, semen quality improved, which led to pregnancy in 14% of the subjects' partners.

Another study showed similar results, with reduced oxidative stress and improved sperm count and motility in infertile men (link). Testosterone levels increased significantly, while prolactin decreased. This is interesting, because prolactin counteracts the effect of dopamine. Dopamine is responsible for sexual arousal and motivation, while prolactin is thought to cause the sexual refractory period after an orgasm. High levels of prolactin cause impotence and loss of libido. The increase in testosterone and decrease in prolactin may therefore explain some of the claimed positive effects of ashwagandha on motivation and libido.

Some of the evidence on ashwagandha and libido is contradictory, however. When male rats were given 3,000 mg/kg of the root extract for 7 days, a marked impairment in libido, sexual performance, sexual vigour and penile function was seen (link). The authors state that since no change in testosterone levels was seen, the negative effects may be due to an increase in prolactin levels or the activity of GABA and serotonin. The increase in prolactin is interesting because it's opposite to what was seen in the study on humans. Note, however, that the dose used here was much higher than in the other rodent studies – perhaps the dose-response curve is U-shaped and more is not necessarily better.

Ashwagandha, stress and memory function

In mice, ashwagandha improves retention of a passive avoidance task (link). In this task, the mouse learns to refrain from stepping through a door to an apparently safer but previously punished compartment, which allows their memory to be assessed. The dosages used were 50, 100 and 200 mg/kg orally. The treatment also reversed the negative effects of scopolamine and electroconvulsive shocks on memory. Furthermore, mice and rats seem to do better on a forced swimming test when treated with ashwagandha (link, link).

Korean red ginseng, also known as Panax ginseng, is also called an adaptogen and shown to be helpful in treating stress. In a study comparing the two, both Panax ginseng and ashwagandha alleviated stress-related conditions such as sexual dysfunction, cognitive deficits and depression in mice subjected to footshocks (link). Ashwagandha was given orally in a dose of 25 or 50 mg/kg and was apparently more effective than Panax ginseng.

Acetylcholinesterase (AChE) is an enzyme that degrades the neurotransmitter acetylcholine, which is a facilitator of memory formation. AChE inhibitors increase the availability of acetylcholine, presumably leading to an improvement in memory. They can be extremely harmful in high doses: AChE inhibitors occur in natural venoms and poisons and are also used in nerve gases. However, AChE inhibitors are also used for medicinal purposes, for example to treat Alzheimer's disease. Huperzine A and galantamine, which are used for memory support and as nootropics, inhibit acetylcholinesterase. Ashwagandha appears to be an AChE inhibitor as well, with methanol extracts being more potent than water extracts (link).

In memory-deficient mice with neuronal atrophy and synaptic loss in the brain, withanolide A – an extract of ashwagandha – induced significant regeneration of nerve fibers and dendrites, as well as a reconstruction of pre- and postsynapses in the neurons (link). Treatment with the extract resulted in a reversal of the memory deficit. Two other extracts, withanoside IV and withanoside VI, appear to have similar effects (link). Ashwagandha or its extracts could thus be used to reconstruct neuronal networks.

Methanol extracts and withanolides are not the only useful part of ashwagandha, however. One study showed that even a withanolide-free water extract of ashwagandha roots had significant antistress activity (link).

Conclusion & my self-experiment

The evidence supports the claims that ashwagandha is an adaptogen and a nootropic. While there are no studies showing that ashwagandha improves mood per se, it does have a range of benefits.

The relaxing and anti-stress effect can be at least partly attributed to the fact that ashwagandha acts as a GABA agonist. It also improves stress-related memory problems by acting as a AChE inhibitor, and has the ability to prevent cognitive degeneration and even reconstruct neuronal networks.

Ashwagandha also seems to correct hormonal imbalances and reduced libido in men by increasing testosterone and decreasing prolactin. Very high doses may have the opposite effect, however.

For the purposes of my own human experiment, I have a bottle of NOW Foods' Ashwagandha extract. The bottle contains 90 capsules with 450 mg of root extract standardized to a minimum of 4.5% total withanolides. Once again, the measuring stick will be my own subjective evaluation of my mood, stress level and libido. Stay tuned for a conclusion of the experiment once I've finished the bottle.

Meanwhile, if you've tried ashwagandha, feel free to drop a comment about your experience. For more information on cognition, stress, mood and libido, see these posts:

Nootropic Battle Conclusion: Acetyl-L-Carnitine vs. Ginkgo Biloba vs. Taurine
Green Tea Protects from the Psychological Effects of Stress in Rats
The Effect of Maca Root on Energy and Libido – Experiment Conclusion
Caloric Restriction Improves Memory in the Elderly

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32 kommenttia:

Anonymous February 13, 2010 at 7:05 AM  

Hi, this is nootrope from ImmInst. I follow your blog regularly. Glad to see you are trying ashwagandha. I believe it has been very beneficial for me.

Anonymous February 13, 2010 at 10:20 AM  

Ihan rakentavassa mielessä huomauttaisin, että yksi olennainen tekijä minkä vuoksi minä ja monet muut blogeja seuraavat, on mahdollisuus päästä keskustelemaan bloggaajan kanssa kommenttiosastolla. Tällä blogilla tuo vuorovaikutus näyttäisi toistaiseksi olevan aika vähäistä.

Mutta muuten kyllä blogisi vaikuttaa mainiolta: jutut ovat kiinnostavia, informatiivisia ja miellyttäviä lukea ja katsella. Jatka tältä osin samaan malliin!

JLL February 14, 2010 at 11:59 AM  


Thanks for the comment and nice to see you here. What kind of effects have you noticed from ashwagandha then?


Kiitos palautteesta & duly noted ;)


Jacey February 15, 2010 at 6:12 PM  


You forgot a very important part of the documented health effects of this herb, which is that it regulates the thyroid gland. Any disturbance in this gland = negative mood effects.

Some references here, scroll down to ashwagandha:

Also, in the libido study where rats got large doses and there where no effects this is of course because ashwagandha is sedating (= somnifera) in large doses, whereas it is stimulating in smaller doses. This has been proven in modern research as well as stated time and again in most ayurvedic books which includes info on the herb.

I grow it myself in my winter garden and most people I give some herb to say it is good for their mood. I have never experienced any difference in my own moods however, but I am not a particularly moody person either.

Nalle February 15, 2010 at 6:56 PM  

Hi, just thought I'd let you know I really enjoy you blog! It's extremely well written and the advice is top notch! Today I actually pulled up your post on oils/cooking right on my iphone when I was at the store (ended up with butter!). Thanks, and keep up the good work!

Nalle, Sthlm

JLL February 15, 2010 at 7:36 PM  


I suppose you're right about the thyroid gland and mood -- I did come across this paper referenced in the article, but I thought I'd save it for another post dealing with the other health effects of ashwagandha. What kind of doses do you use with the herbs in your own garden? I thought the 5 grams used in one study was a fairly large dose, and yet the results were positive.


Thanks for the encouraging words, I hope you stick around!


Jacey February 16, 2010 at 1:10 AM  


I don't bother with exact doses and usually only use a tablespoon in tea along with other adaptogens. Or I make tincture with 50/50 alcohol and herb.

As you may already know you can use smaller doses of adaptogens if you use 2 or moore at the same time as the herbs catalyze each others positive health effects.

About hypothyroidism and mood:

I noticed someplace else in your blog you wanted to increase testosterone in your body. If you have any problems with your thyroid you can forget about that, since the thyroid hormones controll testosterone activity. Hypothyroidism also increases the amount of sex hormone binding globulin (SHBG), which binds to and inactivates any free testosterone that may be around.

Any kind of soy food or substance blocks hormone production in the thyroid, which is why soy is used in animal feed to make the animals fat as fast as possible without having to give them more feed.

Also, a sure way to block testosterone production is to use soy or soy products (that has not been fermented for at least 2 years to neutralize the anti-nutrients/goitrogens), and it has been known for centuries in Asia among wives that soy decreased their husbands libido, a sure way for the wives to avoid sex when they didn't want it.

If you check the real research, and don't rely on soy industry founded research about soy and soy isoflavones you'll find the facts for yourself.

Summary: any food or food substance that mess with the thyroid gland mess with testosterone. And among these soy is the worst.

A last note is that you are misguided about the effectivity of DHT compared to free testosterone as DHT is the most active form of testosterone. And modern science has proven beyond doubt that the DHT theory of male baldness and BHP is wrong, as exess estrogens is the real cause. Info:

JLL February 16, 2010 at 10:33 AM  


Thyroid glands or not, soy isoflavones (in moderate amounts) increase testosterone and reduce DHT in humans and in rodents. Not sure how you separate the "real" research from the "industry funded" research, but that's what the studies show.

I've read that old wives tale before. Maybe there's truth to it, maybe there isn't.

If excess estrogen and not DHT is the culprit of hair loss, why is finasteride so effective? Finasteride reduces DHT, an antagonist of estrogen, and thus exposes you to more estrogen. There are side effects, of course, but it does grow hair.

Jacey February 16, 2010 at 4:38 PM  

No it does not, only in research based on manipulated findings. You must be stupid if you actually believe there is no difference between true science and science based on financial motives. Old wives tale? You do have some useful knowledge about what you do, but then you take into account bullshit that just mess up the whole picture.

If you go through the real research starting from the 70's you'll find the modern results to be plain wrong. It is simply not possible. Soy isoflavones, genistein and dadzein act like estrogens in the body, and there's no chance in hell they could raise testosterone levels. How is it possible to promote science as you do and still don't understand a bit?

And these isoflavones are the main reason soy is used in animal feed since they, being estrogens and goitrogens, block thyroid function making the animals fat fast and at the same time stimulating insulin activity, which also make the body go into storage mode.

And about estrogens being the cause for that DHT gets the blame for:

Also, finasteride does NOT reduce dht, but simply blocks dht's activity in the hair follicles by inhibiting 5-alpha reductase.


Moren on soy health effects, which is based on sound research and not about what the folks in weston-a-price foundation "feel" about soy:

And this ends my comments in here. I talk about true science where you read what you like and promotes it as facts just because it fits your opinion. Much of which is plain bullshit.

JLL February 16, 2010 at 5:28 PM  


Most if not all of science is financially motivated. I'm not questioning that -- what I am questioning is your ability to know which studies are trustworthy and which aren't. It seems that the ones that support *your* view are trustworthy, and the ones that contradict it are corrupted.

What exactly is the real research? None of your links are to actual scientific papers.

What does the effect of soy on insulin have to do with this discussion?

I don't understand what you mean by finasteride "simply blocking DHT's activity". Taking finasteride orally inhibits 5-alpha-reductase and reduces plasma DHT levels. See this paper, for example:

"All patients received finasteride, 5 mg/day, for 6 weeks. All of the above mentioned studies were repeated at month 3 and month 6. All of the patients had baseline hormonal values within the normal range. At month 3, the dihydrotestosterone level decreased by 60%, while the testosterone level increased by 15%."

I think it's pretty ironic that you talk about true science and then link to Dr. Shmercola's site ;) But hey, I'm not begging you to stay if you don't find the blog helpful. Good luck and take care,


Anonymous February 18, 2010 at 10:39 PM  

Have you tried any other nootropic before?

Anonymous March 15, 2010 at 7:31 AM  

A good herb

I am more alert in the day, and sleep better at night. I feel less inclined to drink alohol and coffee.


Laura April 13, 2010 at 7:15 AM  

I note that there is no follow-up post on ashwagandha on your blog. Is that because you noted no benefit?

JLL April 13, 2010 at 9:18 AM  


No, it's because the experiment is still running -- once the bottle is finished, I'll post the conclusion.


Anonymous May 24, 2010 at 12:10 AM  

I feel I benefit from herbs cognitively and physically, so much so that I never take just one because I don't want to miss out on the benefits. This said, I usually take ashwagandha at least once a day and have experienced the following: sedation at low doses (may interfere with my work day requiring attentive energy), spontaneous erections (usu. accompanied by thoughts of fantasy or the sight of an attractive woman) which occurs inside a few hours of ingestion but not later, increased virility/strength, and when taken frequently I feel it may have resulted in the adverse effect of causing chelitis. I used to take it as a strategy to prevent andropause but have concerns about its testosterone lowering effects on rats. I noticed different results with different brands, and I am speaking to one brand that I feel has been giving me acceptable results while another brand seemed to affect my libido in a weird and negative way.

Anonymous September 13, 2010 at 8:46 AM  

Post an update please!

Anonymous March 13, 2012 at 3:02 PM  

Did you experience any tolerance? Did you have any withdrawal symptoms when you stopped taking it?

JLL March 13, 2012 at 9:48 PM  




Anonymous July 27, 2012 at 3:35 AM  

I love ashwagandha, it's gives me sexual stamina like a horse. It has other benefits like it helps me sleep. I cycle it through different herbs. Definitely one of the top herbs on my list.

Buy some at herbalcom [dot] com

They sell in bulk at really low prices. Love that store.

Anonymous August 12, 2012 at 1:50 AM  

I am taking Ashwaganda. I started out taking a whole (470 mg) table. I am a female, age 68, 123 lbs. I felt sick soon after taking it. Tried once more next day - same thing, but I noticed that about 2 hours later I started to feel really good. Now I am taking about 1/3 of a capsule twice a day (not at night) and feel really great. More is not necessarily better.

Anonymous October 3, 2012 at 12:51 AM  

my brother had some problem with epilepsy he is a power lifter .2 year before he had a worse typhoid after it the problem started.on epileptic drugs fits are gone but there is a strength loss and fat gain.he was on sodium valproate mainly with combinations but after he discovered strength loss is due to these drugs he stopped taking them.and then the fits started to come again then he started on ashwgandha500mg root extract with vit b6 25 mg morning and evening with zinc,selenium and magnesium and after some time fits disappeared he gained strength again .he was suffering from severe headaches and results started first by reduction on those headaches which disappeared totally after 5-6 months his mood is better now he was also suffering low memory problem which is also recovered very effectively and no side effects he is taking ashwagandha for over a year now.

Anonymous February 7, 2013 at 6:54 PM  

I am 34 years male, using Ashwagandha capsules 1 capsule/twice a day. I has helped me in loosing some fat and gaining some muscles, I had low concentration which also has improved after I started taking Ashwa. I don't know abt test boosting capability but I am having better sexual desire with this.
and I am having this from last 5 months and had no need to cycle it off.

Anonymous April 29, 2013 at 1:56 AM  

I took 69 pills -once a day- of ashwagandha from a gym who sells their brand. It stimulated my thyroid very badly. I was tested, my doctor had me stop the pills. My thyroid hormones went crazy. I have symptoms of hyperthyroidism, I sweat excessively 15 to 20 times a day, It is a nightmare. Doctor told me I may be better in a month!Be careful before you take this ashwagandha.

Anonymous June 27, 2013 at 2:56 AM  

I am female,28. Firstly I took ashwa from one producer-it was magic, i took 2capsules of 400mg a day-for 2weeks. My libido went up by 200% then the effect dissapeared,and I doubled dosage for a week-my libido went up only a little :-( Now I have ordered ashva from another producer and I see no effect at all,no matter whether I take 250mg or 1g a day. WHAT IS WRONG? does organism so easily get used to this substances,or is it a matter of "cycling" the dosage,or is it possible that another brand may not work (so called herbal supplements hardly ever have a % of withanolides mentioned). Do U experience similar problems? What brand and dosage,and 'system' would U recommend for boosting libido?

HT July 21, 2013 at 2:09 PM  

Interesting blog .... I am nearly 70 years old, I was feeling very tired, difficult to concentrate on my work, wanted to sleep. I also was in a bad mood frequently, was easily emotionally disturbed, and was suffering memory loss.

After taking 10 drops tincture (70% Alcohol), two times per day, for last 6 weeks, my memory and mood are much improved, I sleep better, much less tired in day, my libido is stronger, and I have a strong sense of well being, which has not been present for a very long time. I can now compete better with colleagues half my age, and they have noticed the change.

HT July 21, 2013 at 2:12 PM  

Interesting blog .... I am nearly 70 years old, I was feeling very tired, difficult to concentrate on my work, wanted to sleep. I also was in a bad mood frequently, was easily emotionally disturbed, and was suffering memory loss.

After taking 10 drops tincture (70% Alcohol), two times per day, for last 6 weeks, my memory and mood are much improved, I sleep better, much less tired in day, my libido is stronger, and I have a strong sense of well being, which has not been present for a very long time. I can now compete better with colleagues half my age, and they have noticed the change.

Espalda Plateada November 28, 2013 at 7:02 PM  

Buenas, os dejo un enlace sobre el Ashwagandha, sus propiedades
y donde conseguirlo.

Hasta otra!

poslovodza January 30, 2014 at 6:10 PM  


It's a long time ago, what were the results of the self-experiment?

Thank you.

JLL January 31, 2014 at 11:47 AM  


The update (and conclusion, sort of) was posted here:

Ashwagandha as a Nootropic – Experiment Update


Anonymous February 23, 2014 at 2:01 AM  

Good blog. I've been interested in ashwagandha. I am also trying to support findings about herbs for my blog. My I post a link?

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Anonymous April 30, 2015 at 8:10 AM  

3 grams/kg for negative sexual effects in rats? Why not test 10g/kg or 50 g/kg? Those doses make as much sense: very little. A 75 kg man would need to dose 225 grams ( about 7.5 ounces) to see the same effect. I'd be shocked at any supplement that did not have a negative effect at anything approaching 1/4 of that or less.

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