VoltraAshwagandha for stress and sleep: what the evidence shows
In five small trials, all in India, ashwagandha extract gave a small but statistically significant improvement in sleep, larger in people with insomnia [1]; for stress, reviews disagree, from a clear effect to no significant effect on perceived stress [4] [6]. It's usually well tolerated for up to about 3 months, but rare liver injury, thyroid effects and interactions with some medicines have been reported [8] [9]. It's illegal to sell in Denmark, France advises some groups not to take it, and the Netherlands advises consumers not to use it [10] [13] [14].
Sleep: a small effect in a few trials
The main review of ashwagandha for sleep, from 2021, pooled five randomised trials with 400 participants, all in India, lasting 6 to 12 weeks [1]. Against placebo, ashwagandha extract had a "small but significant effect on overall sleep": a standardised mean difference (SMD) of −0.59, where an SMD is the difference between the groups divided by the spread of scores, so different sleep measures can be pooled [1]. The review rated the evidence moderate quality, and no serious side effects were reported [1].
The effect was larger in adults diagnosed with insomnia, in trials that used 600 mg a day or more, and in trials of 8 weeks or longer [1]. Those are the amounts the trials used, not a dose to take.
Some caveats. The trials were small, and the review found serious imprecision in most of its sleep results for that reason [1]. Its pooled result lists "five trials; 1764 participants", more than the 400 people in those trials: it appears to count each sleep measurement separately, not people [1]. And placebo helped too: in one of the trials, self-rated sleep quality improved by 72% on the extract and by 29% on placebo [8].
A 2025 review of 14 trials in people with mental disorders, most commonly anxiety disorders, found better sleep quality (4 trials) and less stress (3 trials) with ashwagandha, but rated the certainty of the evidence low; the trials lasted a median of 8 weeks [3].
For how much sleep adults need, and the Saudi health ministry's sleep tips, see our guide to how many hours of sleep you need. Our guides to magnesium and melatonin cover the other supplements sold for sleep.
Links to the makers
Four of the five sleep trials used KSM-66, a root extract [1]. Three of those four say the extract came from its maker, Ixoreal Biomed, two of them as a gift, while declaring no financial support [2]. The fifth trial, which used a root and leaf extract (Shoden), was partly sponsored by its manufacturer [1]. The review itself was unfunded, and its authors asked extract makers for more trials but got no reply [1].
Stress: the reviews disagree
Reviews of ashwagandha for stress have reached very different answers:
| Review | Studies | What it found |
|---|---|---|
| Akhgarjand 2022 [4] | 12 (1,002 people) | Stress fell (SMD −1.75); low-certainty evidence |
| Arumugam 2024 [5] | 9 (558 people) | Perceived Stress Scale 4.72 points lower than with placebo |
| Albalawi 2025 [6] | 6 on stress (488 people in all) | No significant effect on perceived stress (SMD −0.355) |
| Marchi 2025 [3] | 3 on stress | Stress fell (SMD −0.95); low certainty; people with mental disorders |
An SMD below zero means less stress than in the comparison group [3]. Two of these reviews also found lower levels of cortisol, a stress hormone [5] [6] [8].
The newest review we found, from June 2026, pooled trials of ashwagandha against placebo for perceived stress and sleep quality. It concluded that the herbal products it covered show possible benefits, but that confidence in the size of the effects is limited by inconsistent results between studies, small-study effects and the quality of reporting [7]. NIH's Office of Dietary Supplements adds that because studies used different preparations and doses, "it is difficult to identify specific extracts or recommended amounts" [8].
Safety: liver, thyroid and medicines
NIH's Office of Dietary Supplements says: "Ashwagandha appears to be well tolerated for up to about 3 months of use, but its long-term safety is not known." [8] Common side effects, such as loose stools, nausea and drowsiness, are usually mild [8].
- Liver. Cases of liver injury have been reported in people taking products labelled as containing ashwagandha. NIH's LiverTox database says: "Typically, the liver injury presented 2 to 12 weeks after starting ashwagandha usually with a cholestatic or mixed pattern of injury, jaundice, and pruritus." [9] Pruritus means itching. Most cases settle within 1 to 4 months of stopping, but rare cases have been fatal or needed an emergency liver transplant, particularly in people with existing liver disease and cirrhosis [9]. Products weren't tested in every case [8], but in several cases the product was tested and contained ashwagandha without other contaminants [9]. LiverTox rates ashwagandha a likely cause of liver injury (likelihood score B) and says "its use should be avoided in patients with cirrhosis or advanced chronic liver disease" [9].
- Thyroid. It might affect thyroid function, and three case reports describe thyrotoxicosis, a thyroid disorder, in women taking ashwagandha extract; their symptoms went away when they stopped [8].
- Medicines. It might interact with thyroid hormone medicines, and the Office of Dietary Supplements adds: "Ashwagandha might also interact with other medications, including antidiabetes medications, antihypertensives, immunosuppressants, and sedatives" [8].
- Pregnancy and prostate cancer. "Some experts advise against the use of ashwagandha by women who are pregnant and by men with hormone-sensitive prostate cancer." [8]
Where it's banned or restricted
| Where | Status |
|---|---|
| Denmark | Illegal to sell [10] |
| France | Advice: some groups shouldn't take it; not a ban [13] |
| Netherlands | Advice: consumers shouldn't use it, especially in pregnancy [14] |
| Sweden | Waiting for an EU review [15] |
| EU | Recommended for EU-level review; we found no decision [16] |
| Saudi Arabia | Products on the SFDA's herbal medicines list [17] |
| UAE | Registered as natural source medicines, pharmacy only [18] |
| Kuwait | We couldn't find its rules |
Denmark. The Danish Veterinary and Food Administration says it is illegal to sell products containing ashwagandha in Denmark. It cites a risk assessment by the Technical University of Denmark (DTU) that found negative effects on sex hormones and reproduction in men and women, and says the plant can affect metabolism, the immune system and the central nervous system [10]. That 2020 assessment concluded that, on the data available, no limit could be set for intake of the root or its extracts below which there would be no risk of harmful effects [11]. In January 2025, the agency warned consumers against three supplements sold online whose illegal plant ingredients included ashwagandha, which it said can harm the immune system and thyroid function [12]. We couldn't find an official date for when the sales ban began.
France. In April 2024, France's food safety agency, ANSES, recommended that people with thyroid, liver or heart disease or high androgen levels, pregnant women, and people taking sedatives or other treatments that depress the central nervous system avoid supplements containing ashwagandha. As a precaution, it said the same for breastfeeding women and under-18s [13]. It's advice, not a ban.
The Netherlands. The Dutch public health institute says: "As a precaution, RIVM advises consumers not to use herbal preparations containing Withania somnifera, especially during pregnancy." [14] It notes that doctors have reported harmful effects on the liver and on thyroid hormone and cortisol levels in people taking these supplements [14].
Sweden and the EU. Sweden's food agency says ashwagandha is one of 12 common supplement ingredients currently under EU review; it is waiting for that review and hasn't made its own risk assessment [15]. In June 2024, a working group of the heads of European food safety agencies listed Withania somnifera among 13 substances it considers a possible health risk, and recommended them for the EU procedure that can ban or restrict a substance in food, or put it under review [16]. We found no EU decision.
The Gulf. In Saudi Arabia, ashwagandha products appear on the Saudi Food and Drug Authority's list of herbal medicines and vitamins [17]. The UAE's Emirates Drug Establishment directory has 14 listings with ashwagandha in the product name, all classed as natural source medicines and sold only in pharmacies [18]. We found no warning, recall or ban on ashwagandha in either country, and we couldn't find Kuwait's rules.
Jordan. A Jordanian news site reported that Jordan's Food and Drug Administration suspended about 17 ashwagandha products from early August 2024, after seeing misuse and side effects on the liver and digestive system, and lifted the suspension in September 2024 [19]. We couldn't retrieve the authority's own notice.
In Voltra
If you take ashwagandha, you can log it in the Eat tab like any food, by searching for it or describing it, and the Coach can answer questions using what you've logged.
Frequently asked
Does ashwagandha help you sleep?
A little, in small trials. Five trials in India found a small but statistically significant improvement in sleep, larger in people with insomnia. Several of them had links to the maker of the extract they tested.
Does ashwagandha reduce stress?
The reviews disagree. Some found clear drops in stress scores; a 2025 review found no significant effect on perceived stress. Two reviews rated the evidence low certainty.
Is ashwagandha safe?
It seems well tolerated for up to about 3 months, but its long-term safety isn't known. Rare liver injury, thyroid effects and interactions with some medicines have been reported, and some experts advise against it in pregnancy and for men with hormone-sensitive prostate cancer.
Is ashwagandha banned?
It's illegal to sell in Denmark. France advises some groups not to take it, and the Netherlands advises consumers not to use it. In Saudi Arabia and the UAE, products are registered as herbal or natural source medicines, and we found no Gulf warning, recall or ban.
Sources
- Cheah KL, Norhayati MN, Husniati Yaacob L, Abdul Rahman R (2021). Effect of Ashwagandha (Withania somnifera) extract on sleep: a systematic review and meta-analysis. PLoS One 16(9):e0257843. Abstract and full text. Five trials, 400 participants, all in India.
- Langade D, et al. (2019); Salve J, et al. (2019); Kelgane SB, et al. (2020). Three of the KSM-66 trials pooled by Cheah 2021: Cureus 11(9):e5797, 11(12):e6466 and 12(2):e7083. Methods, acknowledgements and disclosures of each trial (PMC6827862, PMC6979308, PMC7096075).
- Marchi M, Grenzi P, Travascio A, et al. (2025). The effect of Withania somnifera (Ashwagandha) on mental health symptoms in individuals with mental disorders: systematic review and meta-analysis. BJPsych Open 11(6):e260. Abstract and full text. 14 studies in people with mental disorders.
- Akhgarjand C, Asoudeh F, Bagheri A, et al. (2022). Does Ashwagandha supplementation have a beneficial effect on the management of anxiety and stress? A systematic review and meta-analysis of randomized controlled trials. Phytother Res 36(11):4115–4124. Abstract.
- Arumugam V, Vijayakumar V, Balakrishnan A, et al. (2024). Effects of Ashwagandha (Withania somnifera) on stress and anxiety: a systematic review and meta-analysis. Explore (NY) 20(6):103062. Abstract.
- Albalawi AA (2025). Dual impact of Ashwagandha: significant cortisol reduction but no effects on perceived stress. A systematic review and meta-analysis. Nutr Health 31(4):1395–1408. Abstract.
- Baune BT, Patel MM, Patel MV, Gupta SN (2026). Ayurvedic dravya-based herbal products for cognition, stress, sleep, and psychiatric symptoms: a node-resolved systematic review and meta-analysis. J Integr Complement Med, online ahead of print, 26 June 2026. Abstract.
- NIH Office of Dietary Supplements (2025). Ashwagandha: is it helpful for stress, anxiety, or sleep? Fact sheet for health professionals. Updated 2 May 2025. Efficacy (sleep) and safety.
- National Institute of Diabetes and Digestive and Kidney Diseases (NIH) (2024). LiverTox: Ashwagandha (last update 3 December 2024). Hepatotoxicity, and outcome and management.
- Fødevarestyrelsen (Danish Veterinary and Food Administration). Ashwagandha i kosttilskud og drikkevarer. In Danish. Undated web page.
- DTU Fødevareinstituttet (National Food Institute, Technical University of Denmark) (2020). Risikovurdering af roden fra Withania somnifera (15 May 2020). In Danish. Conclusion, pp. 1–2.
- Fødevarestyrelsen (2025). Fødevarestyrelsen advarer mod kosttilskud der kan skade organer og nervesystem (press release, 16 January 2025). In Danish.
- Anses (French Agency for Food, Environmental and Occupational Health and Safety) (2024). Avis relatif aux risques liés à l'utilisation des préparations de Withania somnifera (L.) Dunal dans les compléments alimentaires. Saisine n° 2021-SA-0077 (19 April 2024). In French. Conclusions and recommendations, p. 46.
- de Heer JA; RIVM (National Institute for Public Health and the Environment, Netherlands) (2024). Risk assessment of herbal preparations containing Withania somnifera (Ashwagandha). RIVM letter report 2024-0029. Synopsis, p. 3.
- Livsmedelsverket (Swedish Food Agency) (2025). Livsmedelsverket omarbetar informationen om ashwagandha (2 May 2025); and Växtbaserade kosttillskott. In Swedish.
- Heads of European Food Safety Agencies; BVL (Germany) (2024). First report of the HoA working group “Food Supplements” (6 June 2024). Summary, section 2.3 and Annex C.
- Saudi Food and Drug Authority (2026). Herbal drugs list, searched for “Ashwa” (accessed 30 September 2026). The product detail pages would not open.
- Emirates Drug Establishment (2026). Registered medical product directory, product name “ashwagandha” (dataset refreshed 30 September 2026). 14 listings, each classed as a natural source medicine, pharmacy only (P).
- زاد الأردن الإخباري (٢٠٢٤). الاردن .. فك تعليق المستحضرات الطبيعية المحتوية على الأشواغندا (١٥ سبتمبر ٢٠٢٤). In Arabic. A news report; we could not retrieve the authority's own notice.
Sources checked on 30 September 2026.
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