Ashwagandha Side Effects: Liver, Thyroid, Pregnancy and Who Should Avoid It

Ashwagandha is usually well tolerated in clinical trials, but it is not risk-free. The most important concern is rare liver injury. This guide covers the common side effects, the liver evidence, thyroid and hormone effects, pregnancy, and who should avoid ashwagandha. For what it can do, see ashwagandha benefits.

The short answer

• Most side effects in trials were mild. [1][2]
• Liver injury is rare but documented: usually jaundice and itching after weeks of use. Most people recovered after stopping; people with existing liver disease have died. [3][4]
• Ashwagandha slightly raises the thyroid hormone T4 and raises testosterone in men. [5]
• Evidence on pregnancy is inconclusive, so avoid it while pregnant. [6]
• Long-term safety has not been established. [1][2]

Common side effects

In a 2024 meta-analysis of 9 randomised trials on stress and anxiety, 4 trials reported mild to moderate side effects, and the authors say more information is needed on long-term use. [1] A 2021 meta-analysis of 5 sleep trials reported no serious side effects but noted that data on serious side effects are limited. [2] Because ashwagandha is studied for sleep [2], take care if you also use sleeping tablets or other sedating medicines, and ask a doctor or pharmacist first.

Ashwagandha and the liver

Liver injury linked to ashwagandha is uncommon, but it is now described consistently across several countries.

• A 2026 scoping review found 13 publications covering 25 patients. Liver injury usually appeared after weeks of use, most often as cholestatic injury with jaundice and itching. Most patients recovered after stopping, usually over weeks to months. One patient needed a liver transplant, and three patients with existing cirrhosis died. The authors advise people with advanced chronic liver disease to avoid ashwagandha. [3]
• A 2023 case series from India reported 8 patients with liver injury from single-ingredient ashwagandha products. Five had existing chronic liver disease; three of them developed acute-on-chronic liver failure and died. Testing of the products found only natural plant compounds, with no adulteration or contamination. [4]
• A 2020 case series from Iceland and the US described 5 patients who developed jaundice with nausea, tiredness, itching and abdominal discomfort 2–12 weeks after starting ashwagandha. None developed liver failure, and liver tests returned to normal within 1–5 months in the four patients who were followed up. Four of the five were also taking other supplements, and in one case rhodiola may have contributed. [7]

What to watch for: yellowing of the skin or eyes, persistent itching, nausea, unusual tiredness or abdominal discomfort. Stop taking ashwagandha and see a doctor, and tell them which supplements you take.

Thyroid and hormones

A 2026 meta-analysis of 23 randomised trials found that ashwagandha raised T4 slightly (about 0.61 µg/dL), with no change in TSH or T3. It also lowered cortisol and raised testosterone in men by about 57 ng/dL, but not in women. [5] A 2026 review of reproductive safety reported that human studies show no adverse effects on thyroid function. [6] The changes are small, but people with thyroid disease or on thyroid medicine should ask their doctor before using ashwagandha.

Pregnancy and breastfeeding

Concerns that ashwagandha could harm a pregnancy come mainly from historical reports and regulatory reviews. A 2026 systematic review found that the evidence for harm is inconclusive: animal studies showed no significant reproductive toxicity at doses relevant to people, and some historical claims could not be traced to primary sources. The authors call for better studies. [6] Inconclusive is not the same as safe. Avoid ashwagandha during pregnancy and breastfeeding unless a doctor advises otherwise.

Who should avoid ashwagandha or ask a doctor first?

• People with liver disease, especially cirrhosis, or a history of liver problems. [3][4]
• People who are pregnant, trying to conceive or breastfeeding. [6]
• People with thyroid conditions or taking thyroid medicine. [5]
• People taking sleeping tablets, sedatives or other regular medicines.
• People with autoimmune conditions.
• Children: safety has not been established.

Can you take ashwagandha every day?

Trials have mostly lasted weeks to a few months. Long-term daily use has not been studied well enough to establish its safety. [1][2] Because liver injury has usually appeared after weeks of use [3][7], a few weeks without problems does not rule it out.

For manufacturers and brand owners

• Plan clear label warnings for pregnancy, liver disease and use with medicines, in line with the rules of each market.
• Keep batch records and supplier documents traceable. The 2026 liver review recommends better supplement traceability and pharmacovigilance. [3]
• Ask for a COA with plant part, withanolide content and method, identity test, heavy metals and microbiology. See our ashwagandha supply page.
• Some regulators have reviewed or restricted ashwagandha in food supplements. Check each export market before launch.

Questions about specifications or documents? WhatsApp us.

What the research says

• Side effects in trials were mostly mild; long-term safety is not established. [1][2]
• Liver injury is rare, usually cholestatic and reversible, but severe in people with existing liver disease. [3][4][7]
• T4 rose slightly; testosterone rose in men only. [5]
• Evidence on harm in pregnancy is inconclusive. [6]

These summaries describe published research on the ingredient. They are not claims for any finished product; claims on finished products must meet the rules of the market where they are sold. This article is not medical advice.

Frequently Asked Questions

Is ashwagandha bad for the liver?

Liver injury is rare, but it has been reported in several countries, usually after weeks of use. Most people recovered after stopping. People with existing liver disease have had severe outcomes and should avoid it.

What are the signs of liver problems from ashwagandha?

Yellowing of the skin or eyes, persistent itching, nausea, tiredness and abdominal discomfort. Stop taking it and see a doctor.

Does ashwagandha affect the thyroid?

A 2026 meta-analysis found a small rise in T4, with no change in TSH or T3. People with thyroid conditions or on thyroid medicine should ask a doctor first.

Is ashwagandha safe during pregnancy?

The evidence is inconclusive, which does not mean it is safe. Avoid it during pregnancy and breastfeeding unless a doctor advises otherwise.

Can I take ashwagandha every day?

Trials lasted weeks to a few months, so long-term safety is not established. Watch for signs of liver problems, and ask a doctor if you take other medicines.

References

1. Arumugam V, et al. Effects of Ashwagandha (Withania somnifera) on stress and anxiety: a systematic review and meta-analysis. Explore (NY). 2024;20(6):103062. doi:10.1016/j.explore.2024.103062
2. Cheah KL, et al. Effect of Ashwagandha (Withania somnifera) extract on sleep: a systematic review and meta-analysis. PLoS One. 2021;16(9):e0257843. doi:10.1371/journal.pone.0257843
3. McIntyre D, et al. Ashwagandha (Withania somnifera)-associated liver injury: a scoping review of clinical characteristics and safety considerations. Cureus. 2026;18(5):e109764. doi:10.7759/cureus.109764
4. Philips CA, et al. Ashwagandha-induced liver injury – a case series from India and literature review. Hepatol Commun. 2023;7(10):e0270. doi:10.1097/HC9.0000000000000270
5. Fornalik M, et al. Hormonal modulation with Withania somnifera: systematic review and meta-analysis of randomized-controlled trials. Planta Med. 2026;92(8):790-805. doi:10.1055/a-2802-8363
6. Tallon MJ, et al. A systematic and ethnobotanical review of ashwagandha’s (Withania somnifera) teratogenic and abortifacient potentials. Phytother Res. 2026;40(8):4737-4758. doi:10.1002/ptr.70079
7. Björnsson HK, et al. Ashwagandha-induced liver injury: a case series from Iceland and the US Drug-Induced Liver Injury Network. Liver Int. 2020;40(4):825-829. doi:10.1111/liv.14393