How Ashwagandha Works in the Body | TuttiBear

Ashwagandha (Withania somnifera) acts mainly on two levels: it modulates the hypothalamic-pituitary-adrenal (HPA) axis, the system that coordinates the stress response and the release of cortisol, and it influences GABA signalling, the main inhibitory neurotransmitter of the central nervous system. That is why the effects described in trials — less perceived stress, less anxiety and better sleep — were observed over weeks of regular intake, and were not assessed as an immediate effect ¹².

There is, however, no single "button" that ashwagandha presses. What exists is a set of effects measured in clinical trials, with specific doses and durations, and several gaps still to be clarified — starting with the ideal dose and what happens after you stop. This article explains the mechanism step by step, what the studies actually measured and where popular promises overreach.

What happens in the body when you take ashwagandha?

Start with the HPA axis. When the brain interprets a situation as a threat, the hypothalamus signals the pituitary gland, which in turn stimulates the adrenal glands to release cortisol. It is a useful and temporary response. The problem arises when stress becomes chronic: the axis stays overloaded, cortisol remains elevated and this is associated with disturbed sleep, tension and fatigue.

Ashwagandha appears to dampen that activation. In a systematic review of 9 clinical trials in people with different degrees of stress, supplementation with Withania somnifera reduced cortisol secretion, with no significant adverse effects; the durations studied ranged from 30 to 112 days ¹. A later meta-analysis, with 9 randomised trials and 558 participants, found reductions in serum cortisol, in the Perceived Stress Scale and in the Hamilton Anxiety Scale compared with placebo ³.

The second level is GABA. Ashwagandha appears to modulate GABAergic signalling indirectly, a proposed but not yet established mechanism; the trials on anxiety and stress measured mainly anxiety and stress scales, not the mechanism ². There are also references to an influence on serotonin and acetylcholine, but these mechanisms are less studied and should not be presented as established.

What the trials measure, concretely

It is worth distinguishing what was measured from what is assumed. Trials do not measure "calm" in an abstract way: they use validated scales (perceived stress, anxiety), biochemical markers (cortisol) and, in some cases, measures of sleep and cognitive function.

In a meta-analysis of 12 randomised trials, with 1002 participants aged between 25 and 48, supplementation with ashwagandha extract significantly reduced anxiety and stress compared with placebo, although the authors classified the certainty of the evidence as low; the dose-response analysis suggested a favourable effect on stress in the region of 300–600 mg per day ². The authors themselves classified the certainty of the evidence as low, which is an important warning: the results are consistent in direction, but the quality of the studies leaves room for doubt.

For sleep, a meta-analysis of 5 randomised trials with 400 participants found a small but significant effect on overall sleep quality, more evident in the subgroup of adults diagnosed with insomnia, with doses ≥600 mg per day and durations ≥8 weeks; improvements were also seen in mental alertness on waking and in anxiety level, with no serious side effects reported ⁴.

There is also a systematic review on testosterone in adult men that identified ashwagandha (root and root/leaf extracts) as one of the two extracts with positive effects on testosterone concentrations, in a universe of 32 studies on 13 plants — but only 9 of the 32 studies showed statistically significant increases, so the reading should be cautious ⁵.

How long does it take to notice an effect?

This is the question that frustrates most people starting out. The honest answer: it depends, and there is no single number that can be presented as fact. What the trials indicate is that the effects on sleep were more evident from 8 weeks onwards ⁴; in the review on cortisol, the protocols varied between 30 and 112 days ¹.

In other words, a cumulative effect over weeks is the scenario the evidence supports. There are no data that allow us to say "you will feel it on the third day" or "after a month it is guaranteed". If after 8 weeks of regular intake you notice nothing, it is reasonable to reassess with a healthcare professional rather than increasing the dose on your own.

Doses studied and what a real label says

The doses used in research are not intake instructions — they serve to give a sense of scale. In the meta-analysis on stress, the dose-response analysis pointed to 300–600 mg per day for stress (and up to 12,000 mg/day for anxiety) ²; for sleep, the effects were more marked with ≥600 mg per day ⁴.

For practical context: TuttiBear's Stress Relief Gummies provide 300 mg of ashwagandha extract per serving of 2 gummies, in a jar of 60 gummies, with the direction to chew 2 gummies per day, preferably after a meal. That is, the dose per serving sits at the lower end of the range studied in the trials — which is not an equivalence nor a promise of effect, only a comparison of numbers. Remember that study doses are not intake instructions and that you should not exceed the dose stated on the label.

If you are looking for a fast effect to fall asleep, ashwagandha is not the right tool: the effect described in the trials is cumulative and depends on regular intake. In that case, it makes more sense to look at options such as melatonin or plants traditionally used at night, such as passionflower — each with its own profile and its own warnings. If you combine more than one supplement, do not exceed the recommended doses of each label.

Besides ashwagandha, these gummies include L-theanine (100 mg), GABA (100 mg), vitamin D3 (25 µg, 500% NRV) and vitamin B12 (500 µg, 20000% NRV) per serving of 2 gummies. Vitamin D contributes to the normal function of the immune system and vitamin B12 contributes to the normal functioning of the nervous system ⁶. The label warnings are relevant: not recommended for children, pregnant or breastfeeding women, or people with thyroid disease or autoimmune diseases; in case of liver disease, other diseases or taking medication, you should consult a healthcare professional before use; it may cause drowsiness and, if this occurs, you should not drive or use machines; it contains polyols and excessive consumption may have a laxative effect.

Ashwagandha and GABA: how they relate

Ashwagandha is not GABA, nor is it a sedative. They are different things that act on different levels. Ashwagandha appears to modulate GABAergic signalling indirectly, while GABA taken orally is an amino acid supplemented as such.

In the case of GABA, a randomised, double-blind, placebo-controlled trial in 30 sedentary women with overweight or obesity doing physical exercise tested 200 mg of GABA per day for 90 days and observed improvements in usual sleep efficiency and other emotional parameters; this is a small sample and a specific population, so it cannot be generalised ⁷. If you want to understand this ingredient better, see how GABA works and what daily dose is usually studied.

Who should — and who should not — consider ashwagandha

Ashwagandha is most relevant for those dealing with persistent stress, difficulty switching off or light and interrupted sleep. For occasional stress — a difficult week, an isolated episode — breathing techniques, exercise and sleep hygiene tend to be more effective and immediate.

If your stress is occasional — a tough week at work, the odd argument — ashwagandha is probably not the right tool. For acute situations, breathing techniques, exercise or simply a good night's sleep are usually more effective. Ashwagandha is a medium-term bet, not a panic button.

There are groups where caution is mandatory. Pregnant women, breastfeeding women and children should not take ashwagandha without professional guidance, and it should never be given to children on your own initiative. People with autoimmune diseases, thyroid disease or liver disease, and those taking medication (sedatives, immunosuppressants, thyroid or blood pressure medicines) should talk to a healthcare professional before starting, because of potential interactions. If you have clinically diagnosed anxiety or depression, this does not replace medical care. You can go deeper in does ashwagandha have side effects? What to know before taking it.

Where popular promises overreach

There is a considerable distance between what you read on social media and what the trials show. Let us take it step by step:

• "Eliminates toxins" or "cleanses the body": no scientific basis. The body has its own elimination systems and no supplement speeds them up in any relevant way.
• "Immediate sedative to fall asleep": no. The effect described in the trials was observed with daily intake over weeks, in protocols with defined durations ⁴.
• "Treats anxiety or depression": it is not a treatment. International clinical guidelines for psychiatric disorders assess herbal medicines with demanding criteria, based on level A evidence (meta-analyses or two or more RCTs) ⁸.
• "Increases testosterone in any man": the evidence exists but is mixed — in a review of 32 studies, only 9 showed statistically significant increases ⁵.

It is also worth dispelling the idea that all gummies are the same. The amount of extract per gummy varies greatly between brands, and standardisation in withanolides is not always declared. Reading the label — dose per serving, number of gummies per jar, warnings — is the minimum before comparing products. It may help to read ashwagandha gummies or tablets and ashwagandha daily dose.

If you choose gummies, look for those that clearly state the amount of extract per dose and the standardisation in withanolides, the plant's active compounds. Some declare this standardisation on the label, which allows products to be compared with some confidence; as with any supplement, quality varies from brand to brand. In the case of gummies, added sugar is also a factor to consider for those controlling their intake.

Morning or night? What the evidence allows us to say

There are no trials directly comparing morning intake with night intake, so any categorical statement would be invented. What is known is that the protocols studied used regular daily intake over weeks ¹⁴. The choice of time depends mainly on how you tolerate the product: if you notice drowsiness, it makes more sense at night; if you prefer to support stress management throughout the day, in the morning. The important thing is consistency. See also ashwagandha: when to take it.

The limit of what we know

Ashwagandha is one of the most studied botanical supplements for stress, but the science has clear gaps. It is not known what the optimal dose is for each person, nor how long the effects persist after stopping intake. The certainty of the evidence was classified as low in the meta-analyses on anxiety and stress ². The quality of extracts varies between brands, which makes direct comparisons difficult. And, as with any botanical, there are no authorised health claims in the European Union — only a description of what the studies examined and found ⁶.

In summary: ashwagandha has a plausible mechanism and measurable results in short-term trials, especially in people with high stress. It is not a panic button nor a treatment. If you decide to try it, do so in an informed way, with a dose within what has been studied, for long enough to assess, and combine it with the pillars that truly support wellbeing: sleep, exercise and stress management. To explore the range, see the ashwagandha gummies and the sleep and relaxation category.

Frequently asked questions

How long does ashwagandha take to work?

Clinical trials usually test durations of between 8 and 12 weeks, and the effects on sleep were more evident from 8 weeks onwards. There is no guaranteed timeframe and no immediate effect: it is a cumulative effect that depends on regular intake. If after about 8 weeks you notice no difference, it is reasonable to reassess with a healthcare professional.

Does ashwagandha affect cortisol?

Yes, it is one of the most studied mechanisms. A systematic review of 9 trials in people with stress observed a reduction in cortisol secretion with supplementation, and a later meta-analysis found reductions in serum cortisol compared with placebo. This does not mean it normalises anyone's cortisol or that it replaces medical assessment.

Is ashwagandha a sedative?

No. It is not a sedative and does not cause immediate drowsiness like a hypnotic drug. What the trials describe is a gradual improvement in sleep quality with regular intake, more evident in adults with insomnia and at higher doses. Some products with ashwagandha may cause drowsiness; if this occurs, do not drive or use machines.

Can I take ashwagandha with other sleep supplements?

It depends on the ingredients and your health situation. Each supplement has its own profile and warnings, and combining compounds with an effect on the central nervous system deserves caution. If you take medication, or have thyroid, autoimmune or liver disease, talk to a healthcare professional before combining products.

Does ashwagandha increase testosterone?

The evidence is mixed. A systematic review of 32 studies on 13 plants identified ashwagandha among the extracts with positive effects on testosterone in adult men, but only 9 of the 32 studies showed statistically significant increases. It is not a valid promise for everyone.

Who should not take ashwagandha?

It is not recommended for children, pregnant or breastfeeding women, or people with thyroid disease or autoimmune diseases. In case of liver disease, other diseases or taking medication, you should consult a healthcare professional before use, because of potential interactions.