What is Ashwagandha?

Ashwagandha is the Sanskrit name for the root of Withania somnifera, a nightshade plant traditionally used as a tonic in Ayurvedic medicine. In English, the plant is also known as winter cherry or Indian ginseng. So-called withanolides and various alkaloids are considered the active ingredients, although according to the BfR, it has not yet been clearly established which substances and quantities are actually responsible for the effects observed in studies.

In the EU, Ashwagandha root is approved as a "novel food" and may be used in food supplements; preparations from the plant's leaves, however, are not approved as food. According to the BfR, the type and content of ingredients in individual preparations can vary significantly—depending on whether the root or other plant parts are used and which extraction process is employed.

Important notice: What the BfR says about Ashwagandha

Mechanism of action: How is Ashwagandha supposed to work?

Ashwagandha is classified as an adaptogen—a collective term for plant substances that are attributed with a regulating effect on the body's stress response. The postulated mechanism is a modulation of the hypothalamic-pituitary-adrenal (HPA) axis, which controls the release of the stress hormone cortisol. This mechanism is biochemically plausible and supported by the cortisol changes measured in studies. However, the BfR points out that a clear causal relationship is made difficult by the heterogeneity of the studies and the frequent marketing as a combination product.

Ashwagandha and stress: What do the studies really show?

The most frequently cited individual study comes from Chandrasekhar, Kapoor, and Anishetty (2012, Indian Journal of Psychological Medicine): 64 adults with chronic stress received either 300 mg of standardized root extract twice daily or a placebo for 60 days. Serum cortisol levels in the Ashwagandha group fell by about 27.9 percent compared to about 8 percent in the placebo group, and the perceived stress score (PSS) improved by about 44 percent compared to placebo.

Data source: Chandrasekhar et al. (2012), n = 64, 300 mg 2× daily for 60 days. Individual study – no proof for the entire product category.

A meta-analysis by Akhgarjand et al. (2022, Phytotherapy Research) evaluated 12 randomized, controlled trials with 1,002 participants and found significant effects on anxiety (SMD −1.55) and stress (SMD −1.75). However, the authors themselves rate the quality of evidence as low—the heterogeneity between the studies was very high at I² = 93.8% (anxiety) and 83.1% (stress), meaning the individual studies differed greatly in their results and methodology.

A more nuanced picture is provided by a recent meta-analysis from 2025: While it did find a statistically significant reduction in cortisol levels (−1.16 µg/dl; 95% confidence interval −1.64 to −0.69; p < 0.001), it found no significant effect on subjectively perceived stress. This shows: A biochemically measurable effect on cortisol does not automatically mean that users also feel noticeably less stressed. A placebo-controlled study from 2025 (Journal of Medicine and Life) using 600 mg of Ashwagandha extract daily for 24 weeks additionally reported a drop in serum cortisol of about 36 percent (from 13.91 to 8.90 µg/dl) as well as reduced cravings and weight—though this remains unconfirmed by independent follow-up studies.

Does Ashwagandha also help with better sleep?

The body of evidence regarding sleep quality is even thinner than that for stress and cortisol. Existing review articles mostly report in the same direction—namely, a slight improvement in sleep quality scores such as the PSQI—but the underlying individual studies differ significantly in dosage, study duration, and the groups of people examined. A study published in 2026 with 200 adults with sleep problems tested 600 mg of Ashwagandha extract daily (divided into 300 mg after breakfast and dinner); however, reliable, independently confirmed long-term data for this area of application is still lacking.

Ashwagandha dosage: What quantities were used in studies?

Side effects, interactions, and who should avoid Ashwagandha

Frequently reported, mostly mild side effects include gastrointestinal complaints (nausea, diarrhea), headaches, dizziness, drowsiness, and skin rashes. Less frequently but more seriously: Since 2017, case reports of liver damage—including cases of acute liver failure—have been published worldwide, including in Europe and Germany. Ashwagandha can also interact with medications that regulate blood sugar (antidiabetics), blood pressure (antihypertensives), or the immune system (immunosuppressants), as well as thyroid medications, as it can influence T3/T4 production while simultaneously lowering cortisol. People with hyperthyroidism or Hashimoto's thyroiditis should therefore be particularly cautious and seek medical advice in advance.

According to the BfR, intake is explicitly advised against for: pregnancy and breastfeeding, children and adolescents, and existing or previous liver disease. Additional caution applies to autoimmune diseases, thyroid disorders, upcoming surgeries (due to possible immune modulation), and the use of long-term medication—here, medical or pharmaceutical advice should always be sought in advance. In the event of signs of liver strain such as yellowing of the skin or eyes, dark urine, or unusual fatigue, intake should be stopped immediately and medical advice sought.

Who might still consider an Ashwagandha supplement?

Given the BfR warning and the ongoing EU review, Ashwagandha is not a supplement that can be recommended across the board. Those who decide to give it a try—provided they do not have the above-mentioned risk factors and have consulted a doctor in case of doubt—should opt for a standardized extract with a transparently declared withanolide content, start with a low dose, and monitor their own tolerance over several weeks.

The Veyt Ashwagandha Root Balance capsules provide a high-dose, vegan, and sugar-free extract without unnecessary additives; those who prefer to dose it themselves can find the same root base in loose form with the Ashwagandha Powder. For men who want to combine Ashwagandha as part of a broader stress and energy routine, the Men’s Strength & Focus Routine adds Ashwagandha alongside Shilajit and Zinc. In any case, please note: These products are food supplements, not medicines, and do not replace a balanced diet or medical clarification of persistent stress or sleep problems.

Frequently asked questions about Ashwagandha

Is Ashwagandha really effective against stress?

Several randomized studies and a meta-analysis (Akhgarjand et al., 2022) show significant improvements in stress and anxiety scores as well as measurable cortisol reductions. However, the quality of evidence is considered low to moderate, the studies are heterogeneous, and a newer meta-analysis from 2025 found an effect on cortisol but no significant effect on subjective stress perception.

How much Ashwagandha should one take per day?

There is no officially recommended daily amount. Studies have mostly used 300 to 600 mg of standardized extract per day, often divided into two doses. So far, the BfR has not been able to derive a guideline value for a safe intake amount.

Why is the BfR warning against Ashwagandha?

In notification 039/2024, the BfR refers to insufficient safety data, case reports of sometimes severe liver damage, as well as possible effects on the immune system, blood sugar, thyroid, and sex hormones. It explicitly advises pregnant women, breastfeeding women, children, and people with liver disease against taking it.

Can Ashwagandha influence the thyroid?

Yes, there are indications that Ashwagandha can influence the production of the thyroid hormones T3 and T4. People with hyperthyroidism or Hashimoto's thyroiditis should therefore absolutely seek medical advice before taking it.

Who should not take Ashwagandha?

According to the BfR, pregnant women, breastfeeding women, children, and people with existing or past liver disease should avoid Ashwagandha. Additional caution is required for autoimmune and thyroid diseases as well as when taking medication for blood sugar, blood pressure, or immunosuppression.

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Sources:

• German Federal Institute for Risk Assessment (BfR): Ashwagandha: Winter cherry preparations with potential health risks. Notification 039/2024, September 10, 2024.
• Chandrasekhar K., Kapoor J., Anishetty S. (2012): A prospective, randomized double-blind, placebo-controlled study of safety and efficacy of a high-concentration full-spectrum extract of ashwagandha root in reducing stress and anxiety in adults. Indian Journal of Psychological Medicine, 34(3), 255–262.
• Akhgarjand C. 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. Phytotherapy Research, 36(11), 4115–4124.
• Systematic review and meta-analysis (2025): Effects of Ashwagandha Supplements on Cortisol, Stress, and Anxiety Levels in Adults. BJPsych Open (PMC12242034).
• Randomized, placebo-controlled study (2025): Efficacy and safety of Ashwagandha (Withania somnifera) root extract on stress and weight management in adults. Journal of Medicine and Life.
• Heads of Food Safety Agencies (EU): Recommendation to initiate a review process under Art. 8 of Regulation (EC) No. 1925/2006 for Ashwagandha, 2024.