Ashwagandha Harms

Short answer

Cases of liver injury have been reported from many countries; most were of the cholestatic type and resolved within months once the product was stopped, but there is a series ending in death in people with prior liver disease. There are also cases of thyrotoxicosis and regulatory warnings on pregnancy, sedative use and thyroid disease. The frequency is unknown.

Does ashwagandha harm the liver?

Several case series and regulatory assessments answer this question with “it can”; the exact frequency is unknown.

Iceland and the US (Björnsson 2020). Five cases: three from Iceland (2017–2018) and two from the US DILIN network (2016); mean age 43, three men. In all, jaundice, nausea, fatigue, itching and abdominal discomfort developed after a delay of 2–12 weeks. The injury was cholestatic or mixed (R ratio 1.4–3.3); itching and hyperbilirubinemia lasted 5–20 weeks. No one developed liver failure; in four patients tests returned to normal in 1–5 months and one was lost to follow-up. One biopsy showed acute cholestatic hepatitis. Ashwagandha was confirmed in the supplements by chemical analysis and no other toxic substance was detected. No patient was using a prescription medicine harmful to the liver; four were taking additional supplements, and in one case rhodiola taken together with ashwagandha was also considered a possible cause. ^[1]

India (Philips 2023). In a multicenter retrospective series, there were 23 patients with ashwagandha-related liver injury between January 2019 and December 2022; when those using multi-ingredient products or another known hepatotoxic substance were excluded, 8 patients associated with a single-ingredient product were reported. The majority were men and the most frequent picture was cholestatic hepatitis. Five patients had underlying chronic liver disease; three presented with acute-on-chronic liver failure and all three died during follow-up. In the others the injury was prolonged but resolved on its own; one patient progressed to chronic injury. Chemical analysis detected only natural phytochemicals; no adulteration or contamination was found in the products. ^[2]

Türkiye (Ministry opinion, 2023). The document adopted on 22/12/2023 by the Commission on Plants That Can Be Used as Food reports that such cases have been notable in the literature since 2017 and summarizes 12 published reports. According to the document, because commercial herbal products can be mixed and mislabeled, in each case it is not clear whether the culprit is the plant, an ingredient or a contaminant; however, in a few cases the product was tested and no other contaminant was found. The document also states that the risk of liver injury may be associated with daily doses higher than traditional use (up to 12,000 mg/day); the possibility of products with added leaf; and that the mechanism is not fully elucidated. In its summary table, the statement “as recommended on the label, no overdose” appears for the Björnsson series. ^[3]

The Netherlands (Lareb). The Dutch Pharmacovigilance Centre warned about liver toxicity in September 2023; according to its July 2025 update, it has received eight new reports since then. Lareb also states that liver toxicity appears rare, that herbal products may contain unlabeled herbs, and that the possibility that the injury in the reports stems from another cause cannot be excluded; it forwarded the reports to the Netherlands Food and Consumer Product Safety Authority. ^[5]

Case series are limited for frequency and cause and effect: they have no denominator and all rest on reports. Even so, the repetition in several countries of the pattern of jaundice, cholestasis and recovery after the product was stopped is the rationale for regulators to act.

Can it cause harm by affecting thyroid hormones?

Thyrotoxicosis has been reported in individual cases. Hayashi and colleagues described a previously healthy 47-year-old Japanese man: he had started ashwagandha two months before presenting to hospital; the patient, who came with fatigue, night fevers, weight loss, diarrhea and headache, was diagnosed with thyrotoxicosis with painless thyroiditis, with absence of uptake on scintigraphy. When ashwagandha was stopped, symptoms and thyroid markers improved. ^[6] In the case of Kamal and colleagues, a 73-year-old woman who had used ashwagandha root extract on her own for two years for hypothyroidism presented with supraventricular tachycardia, symptoms of hyperthyroidism and a markedly low TSH; when the supplement was stopped, symptoms and biochemistry improved. ^[7]

Both cases are single cases; they establish neither frequency nor level of causality. Regulators, however, have made this a subject of warning: the Dutch RIVM (2024) stated that current products may cause liver injury, thyrotoxicosis and suppression of the adrenal system in susceptible people; which people are susceptible is not known. The French ANSES (April 2024) recommended that people with thyroid disease avoid it. The Danish DTU (2020) counted a possible effect on sex and thyroid hormones among its concerns. ^[4]

Is ashwagandha safe in pregnancy and breastfeeding?

The agency warnings on use in pregnancy and breastfeeding are as follows: ^[4]

• Netherlands RIVM (2024): it is recommended in particular that pregnant women not use herbal preparations containing ashwagandha; one of its reasons is that, according to the WHO, the plant has historically been used to induce miscarriage. RIVM states that there are no appropriate reproductive toxicity studies that would exclude this effect.
• France ANSES (2024): pregnant and breastfeeding women are recommended to avoid it.
• Germany BfR (2024): in particular children, pregnant women, breastfeeding women and people with liver disease should avoid it; the general population should also exercise moderation.
• Denmark DTU (2020): its use as a traditional abortifacient was one of the safety concerns.

With which medicines and in which situations can it interact?

There is more an assessment of risk groups than a measured drug-interaction study. ANSES recommended that people using sedatives (sleep-inducing, calming) avoid it; this is consistent with the plant being traditionally regarded as a sedative. ^[4] The Ministry document reports that root extracts of the plant do not inhibit the CYP3A4 and CYP2D6 enzymes; the same document says that the roots are used in traditional medicine as a hypnotic and sedative. ^[3] Among DTU’s concerns are a possible effect on the immune system and acetylcholinesterase inhibition; these are not measured results as drug interactions but concerns about possible effects. ^[4]

What are the common side effects?

Lareb lists drowsiness, diarrhea and abdominal pain as known side effects; it also states that very little research has been done on the safety of ashwagandha. ^[5] According to the Ministry document, mild gastrointestinal side effects of under 5% were seen in some clinical trials; dizziness, drowsiness, vertigo, nasal congestion, cough, loss of appetite, nausea, constipation, dry mouth, hyperactivity, nocturnal cramps, blurred vision, skin rash and weight gain were reported at very low rates. ^[3]

How long is use considered safe?

There is no established duration for this. The authors of the sleep meta-analysis write that data on serious adverse effects are limited and that more safety data are needed to evaluate the safety of long-term use. ^[8] The Ministry document says that use up to 8 months has been reported as safe in preclinical and clinical studies; the case table of the same document, however, lists durations of use between 14 and 540 days among the liver injury cases. ^[3] In the Björnsson series, symptoms began within 2–12 weeks. ^[1] That is, the risk cannot be defined as a situation that appears only with long use.

For whom is ashwagandha not suitable?

A summary combining the agencies’ warnings: ^[4]

• Pregnant and breastfeeding women (ANSES, BfR, RIVM).
• People with liver disease (ANSES, BfR). The three patients who died in the Philips series had presented with acute-on-chronic liver failure; the authors link the high mortality to people with prior liver disease. ^[2]
• People with thyroid disease (ANSES); people with heart disease or hyperandrogenism (ANSES).
• People using sedatives (ANSES).
• Children and adolescents up to 18 (ANSES; BfR mentions children).

What are the regulators doing?

The Ministry of Agriculture and Forestry keeps the root and aerial parts negative (N) on the Plant List; the opinion was adopted on 22/12/2023 and the status is the same in the 16/07/2026 update of the list. ^{[3] [9]} Denmark banned the use of ashwagandha as a food (supplement) in 2023, based on the DTU assessment; according to the review, Poland in 2020 limited daily intake to 3 g of powdered root and at most 10 mg of withanolides (the review’s country table, however, states that use in supplements is not regulated in Poland and is possible by notification to the authorities); in the Netherlands an amendment that would ban its use in supplements if it enters into force was proposed (2025). The Heads of Food Safety Agencies proposed ashwagandha to the European Commission in June 2024 for a priority procedure under Article 8 of Regulation 1925/2006. ^[4] Among the authors of the review from which this country information is reported are people from an industry association, a food regulatory consultancy firm and a law firm.

Detailed guideAshwagandha: general guide→ Detailed guideAshwagandha benefits: which claims are supported?→

This guide does not recommend a personal dose; for people who use medicines, are pregnant or have liver and thyroid disease, the decision is made with a physician.