Is Ashwagandha Safe? Side Effects, the Liver Question and Who Should Avoid It
Ben Law
Reviewed by Sarah Law, Dip CNM, Naturopathic Nutritionist
Is ashwagandha safe? For most healthy adults, a root extract taken at the studied dose appears well tolerated for up to about 3 months, which is the position of the US NIH Office of Dietary Supplements; its long-term safety is not known. Side effects are usually mild: stomach upset, loose stools, nausea and drowsiness. The real concerns are rare cases of liver injury and possible effects on thyroid hormones, which is why the UK Food Standards Agency advises pregnant women and people with pre-existing liver conditions to avoid it while the UK Committee on Toxicity finishes its review. If you are in neither group and want to take it, choose a root-only standardised extract at the trial dose, take it as a course of 8 to 12 weeks, and stop if you notice itching, dark urine or yellowing skin.
Our own Organic KSM-66 Ashwagandha is a root-only extract. Each capsule supplies 600 mg of organic KSM-66 ashwagandha root extract standardised to 5% withanolides (30 mg) and less than 0.1% withaferin A, in a vegetable cellulose capsule with no other ingredients. The label directs 1 capsule daily with food and states it is not intended for anyone under 18. A pot of 60 capsules costs £26.95 on our UK store, 45p a day; it is not currently sold on our US store. Batch Certificates of Analysis are linked from the label QR code, and it is covered by our 60-day money-back guarantee.
- Short-term use: well tolerated in trials of up to about 3 months at 250 to 600 mg a day of root extract. No good data beyond that.
- Common side effects: mild stomach upset, loose stools, nausea and drowsiness.
- Rare but serious: liver injury (usually jaundice and itching 2 to 12 weeks after starting, normally resolving after stopping) and possible thyroid hormone changes.
- Avoid: pregnancy, trying to conceive, breastfeeding, liver disease, under 18. Check first with thyroid or autoimmune conditions, prostate cancer, or regular medication.
- Regulation: legal in the UK and US as of October 2026; banned in Denmark since 2023; UK review still in draft.
Is ashwagandha safe? What the authorities say
No health authority has declared ashwagandha unsafe for everyone, and none has declared it safe for everyone. The common ground across the US and European bodies is that short-term use by healthy adults appears well tolerated, long-term safety is unknown, and specific groups should avoid it. The table sets out each authority's position in its own terms, as published on 17 October 2026.
| Authority | Country | Position (October 2026) |
|---|---|---|
| NIH Office of Dietary Supplements | US | Appears well tolerated for up to about 3 months; long-term safety not known; common side effects mild; a few reports of liver injury; may affect thyroid function and interact with some medicines; some experts advise against use in pregnancy and in men with hormone-sensitive prostate cancer [1]. |
| Food Standards Agency and Committee on Toxicity | UK | Safety review under way since a 2024 call for evidence; a third draft statement was discussed in September 2026 and has not yet been published. While the review is ongoing, the FSA advises people with pre-existing liver conditions and pregnant women to avoid ashwagandha supplements [2] [3]. |
| NHS | UK | No ashwagandha-specific page. Its general advice on herbal products says not to take them if you are pregnant or breastfeeding, have kidney or liver problems, or take certain medicines, and that herbal medicines are not recommended for children [4]. |
| Federal Institute for Risk Assessment (BfR) | Germany | September 2024: children, pregnant and breastfeeding women and people with acute or pre-existing liver disease should not take ashwagandha supplements; others should be cautious; a safe intake level could not be derived [5]. |
| Danish Veterinary and Food Administration | Denmark | Banned ashwagandha in food supplements in 2023, after a 2020 Technical University of Denmark assessment found no safe lower intake could be set [1]. |
| ANSES | France | 2024: recommends against use by certain groups, including pregnant and breastfeeding women and people with endocrine disorders [1]. |
Ashwagandha is a botanical, not a vitamin or mineral, so it has no UK Nutrient Reference Value (NRV) and no US Recommended Dietary Allowance (RDA) or upper limit. Positions summarised from each source on 17 October 2026; the FSA advice is quoted as reported in June 2026 because the COT statement it refers to is still unpublished.
What are the side effects of ashwagandha?
The common side effects of ashwagandha are mild and digestive: stomach upset, loose stools and nausea, plus drowsiness in some people [1]. Germany's BfR adds headaches, dizziness and skin rashes to the reported list [5]. In the clinical trials most people use as a reference, adverse effects were few and similar between ashwagandha and placebo groups: in a 60-day trial of 300 mg of root extract twice daily in 64 stressed adults, side effects were mild and comparable in both groups with no serious events [6], and in a 60-day trial of a different extract at 240 mg a day, all 60 participants completed with no adverse events reported [7].
The most direct safety data come from a trial designed to look for harm. Eighty healthy adults, 40 men and 40 women, took 300 mg of ashwagandha root extract or placebo twice daily for 8 weeks, with blood tests covering blood counts, serum biochemistry including liver markers, and thyroid hormones. There were no significant changes or abnormalities in any of these, including the thyroid profile, and no adverse events; the authors concluded that 8 weeks of use was safe in both men and women, while calling for longer studies and different doses [8]. That is reassuring for a 2-month course; it says nothing about years of use.
Drowsiness is worth planning around. If ashwagandha makes you sleepy, take it in the evening with food and avoid driving until you know how it affects you. Our complete guide to ashwagandha covers timing in more detail.
Can ashwagandha damage your liver?
Rarely, yes, and this is the reason for most of the regulatory attention. The pattern in published cases is consistent. In a case series from Iceland and the US Drug-Induced Liver Injury Network, five people developed jaundice with nausea, tiredness, itching and abdominal discomfort 2 to 12 weeks after starting ashwagandha-containing supplements; the injury was cholestatic or mixed, none developed liver failure, and liver tests returned to normal within 1 to 5 months in the four who were followed up [9]. Chemical analysis confirmed ashwagandha in the products and found no other toxic compounds.
A larger series from India reported 8 people with liver injury from single-ingredient ashwagandha products between 2019 and 2022. Five already had chronic liver disease, and three of those, who presented with acute-on-chronic liver failure, died; in the others the injury was prolonged but self-limiting [10]. Individual cases have also been reported from the UK and Poland [11] [12]. The NIH notes that the contents of the products were not independently verified in every case, and some were combination products [1].
Three practical points follow. First, this is an idiosyncratic reaction: it is rare, unpredictable and not simply a matter of taking too much, so a lower dose is not a guarantee. Second, existing liver disease is the clearest risk factor, which is why the FSA and BfR single out people with liver conditions. Third, the warning signs are recognisable: itching, dark urine, pale stools, yellowing of the skin or eyes, or unusual tiredness and nausea after starting ashwagandha. If you notice any of them, stop taking it and see your GP or doctor promptly.
Does ashwagandha affect the thyroid?
It may. In a placebo-controlled trial in 50 people with subclinical hypothyroidism, 300 mg of root extract twice daily for 8 weeks lowered TSH and raised T3 and T4 compared with placebo [13], and three case reports describe thyrotoxicosis in women taking ashwagandha, one of them at an unusually high 1,950 mg a day [1]. That means ashwagandha can shift thyroid hormone levels, which matters if you take thyroid medication or have an overactive thyroid. If you have any thyroid condition, speak to your doctor before starting, and expect them to want blood tests if you go ahead.
"Before I suggest ashwagandha I ask three questions: are you pregnant or trying to conceive, do you have a thyroid or liver condition, and what medication do you take. If the answer to any of them is yes, ashwagandha is a conversation for your GP first, not a supplement to start on your own."
Sarah Law, Naturopathic Nutritionist | Optimised Female
Who should not take ashwagandha?
These groups should avoid ashwagandha or take advice first. The list combines the NIH, FSA, BfR, NHS and our own label.
| Group | Advice | Why |
|---|---|---|
| Pregnant, trying to conceive, or breastfeeding | Avoid | FSA, BfR and ANSES advise against; some reports suggest a risk of miscarriage, although the American Herbal Pharmacopoeia disputes that this applies to the root [1]. |
| Liver disease, or a past reaction to a herbal product | Avoid | Case reports of liver injury, worst in people with existing liver disease [10]. |
| Under 18 | Avoid | Not studied; our label and the NHS herbal guidance both exclude children. |
| Thyroid conditions or thyroid medication | Doctor first | May raise thyroid hormone levels [13]. |
| Autoimmune conditions or immunosuppressants | Doctor first | Possible effects on the immune system and interaction with immunosuppressants [1]. |
| Diabetes, blood pressure or sedative medicines | Doctor first | Possible interactions; BfR notes effects on blood glucose [1] [5]. |
| Hormone-sensitive prostate cancer | Avoid unless your specialist agrees | Possible effects on sex hormones [1]. |
| Planned surgery | Stop beforehand and tell your surgical team | Drowsiness and possible interaction with sedative medicines; our label asks you to consult your GP if due to undergo surgery. |
Our ashwagandha for women and ashwagandha for men guides discuss the hormone questions in more detail.
Root extract vs leaf: does the type of ashwagandha matter for safety?
It might, and it is the most useful thing to check on a label. Germany's BfR points out that ashwagandha was traditionally used as the root, that leaves are now also appearing in European supplements, and that the plant part and extraction method both change the active compounds in the product [5]. In April 2026 India's government banned the use of ashwagandha leaf, a move several manufacturers then challenged in court [14]. No trial has compared the safety of root and leaf products directly, so we cannot say a root extract is proven safer, but the human safety data that exist are mostly for root extracts.
| Type | Plant part | Standardisation | Daily amount used in trials or on label | Human safety data |
|---|---|---|---|---|
| KSM-66 root extract | Root only | 5% withanolides; no alcohol or chemical solvents in extraction | 300 mg twice daily or 600 mg once daily | Dedicated 8-week safety trial in 80 healthy adults (root extract, 300 mg twice daily) [8]; several 8 to 12 week efficacy trials |
| Sensoril | Root and leaf | 10% withanolide glycosides | 125 to 250 mg | Efficacy trials (the supplier cites more than 14 human studies) |
| Other standardised extracts (for example Shoden) | Varies by brand; check the label | Varies | 240 mg in the trial we cite | 60-day trial, no adverse events reported [7] |
| Plain root powder | Root | Usually none stated | Often several grams | Little product-specific data; withanolide content varies widely [5] |
| Unstated plant part or "whole plant" | Unknown, may include leaf | Unknown | Unknown | None you can rely on; avoid |
| Love Life Supplements Organic KSM-66 | Root only | 5% withanolides (30 mg), less than 0.1% withaferin A | 1 capsule (600 mg) daily with food | Same extract type as the trials above; batch COAs via label QR code |
Sources: our printed label (KSM-66 P11383 v8); NIH ODS fact sheet [1]; trials cited in the table; Sensoril standardisation and dose as stated on Sensoril-branded product listings read 17 October 2026. Withaferin A is one of the withanolides; some brands, including ours, cap it because it is among the most biologically active compounds in the plant. Not every product names its extract, so the most important check is that the label states the plant part.
Organic KSM-66 Ashwagandha: root only, 600 mg per capsule, 5% withanolides, less than 0.1% withaferin A, 60 capsules.
View productHow to take ashwagandha safely
If you are not in one of the groups above and want to try ashwagandha, these steps keep you inside what the evidence covers.
- Choose a labelled root extract. The label should state the plant part (root), the extract or standardisation, and the milligrams per capsule.
- Stay at the studied dose. Trials mostly used 250 to 600 mg of root extract a day [6] [15]. More is not better, and one thyrotoxicosis case involved 1,950 mg a day.
- Take it as a course. Safety is documented for up to about 3 months. An 8 to 12 week course followed by a break keeps you within that window.
- Take it with food. This reduces stomach upset, the most common side effect, and our label directs it.
- Use one ashwagandha product at a time. Check stress, sleep and "adrenal" blends for hidden ashwagandha so you do not double up.
- Know the warning signs. Stop and see a doctor if you develop itching, dark urine, yellowing skin or eyes, or a racing heart.
- Tell your doctor or pharmacist. Especially if you take any regular medicine or are due to have surgery.
"I suggest ashwagandha as a course rather than a forever supplement: one root extract capsule a day with food for eight to twelve weeks, then a break, which matches how long the trials ran. If you notice itching, dark urine or yellowing skin, stop and speak to your GP straight away."
Sarah Law, Naturopathic Nutritionist | Optimised Female
Is ashwagandha banned anywhere?
Ashwagandha is legal to sell as a food supplement in the UK and as a dietary supplement in the US as of 17 October 2026. Denmark banned it in food supplements in 2023 [1], and several other European countries have investigated it or issued warnings; at EU level, heads of national food safety agencies proposed restricting a list of botanicals including ashwagandha in 2024, but no EU-wide review had begun by mid-2026 [14]. In the UK, the Committee on Toxicity discussed a third draft of its ashwagandha statement at its September 2026 meeting, with the content reserved as unpublished [2]. We will update this page when the statement is published. If the UK changes the rules, we will follow them.
Where our ashwagandha stands, and where it does not
We sell ashwagandha, so read this section with that in mind. Our case is narrow and factual: our capsule is a root-only extract at the dose most trials used, with withaferin A capped below 0.1% and no other ingredients, and we tell the same groups to avoid it as the regulators do. What we cannot claim is that it is free of the rare liver risk described above; nobody selling ashwagandha can, because the reactions appear to be idiosyncratic and the long-term data do not exist. We also do not sell it on our US store, so US readers will need a product that meets the same label checks: root only, a named and standardised extract, a stated dose in the 250 to 600 mg range, and a published certificate of analysis. If you are pregnant, trying to conceive or have a liver condition, the right ashwagandha product is none. Our KSM-66 explainer covers how our product is made.
Is ashwagandha safe? Frequently asked questions
Is ashwagandha safe?
For most healthy adults, ashwagandha root extract appears well tolerated for up to about 3 months, according to the NIH Office of Dietary Supplements; its long-term safety is not known. Side effects are usually mild (stomach upset, loose stools, nausea, drowsiness). Rare cases of liver injury have been reported, and it may affect thyroid hormones. Pregnant women and people with liver conditions should avoid it, and anyone with a thyroid condition or on regular medication should check with a doctor first.
Is ashwagandha safe to take every day?
Daily use is how it was taken in the clinical trials, usually 300 mg twice a day or 600 mg once a day of a root extract for 8 to 12 weeks. An 8-week trial in 80 healthy adults taking 300 mg of root extract twice daily found no significant changes in blood tests, including liver and thyroid markers, and no adverse events. Safety beyond about 3 months has not been studied well, so many practitioners suggest a course followed by a break.
Can ashwagandha damage your liver?
Rarely, yes. Published case reports and series describe liver injury, usually cholestatic with jaundice and itching, starting 2 to 12 weeks after people began ashwagandha products; in most cases liver tests returned to normal within 1 to 5 months of stopping. People with existing liver disease appear to be at greatest risk. The UK Food Standards Agency advises people with pre-existing liver conditions to avoid ashwagandha supplements.
Who should not take ashwagandha?
Avoid it if you are pregnant, trying to conceive or breastfeeding, if you have a liver condition, or if you are under 18. Speak to your doctor first if you have a thyroid condition, an autoimmune condition, hormone-sensitive prostate cancer, or take thyroid, diabetes, blood pressure, immunosuppressant or sedative medicines, and stop it before planned surgery.
Is ashwagandha banned in the UK?
No. As of October 2026 ashwagandha is legal to sell as a food supplement in the UK and the US. The UK Committee on Toxicity has been reviewing its safety since 2024 and discussed a third draft statement in September 2026; meanwhile the Food Standards Agency advises pregnant women and people with pre-existing liver conditions to avoid it. Denmark banned ashwagandha in food supplements in 2023.
Is KSM-66 safer than other ashwagandha?
There is no head-to-head safety trial, so no extract can claim to be safer. What KSM-66 offers is a root-only extract, standardised to 5% withanolides and made without alcohol or chemical solvents, with a published 8-week safety trial in healthy adults. Regulators have raised more questions about leaf material, which is not part of traditional use. The same people should avoid KSM-66 as any other ashwagandha.
About the Reviewer: Sarah Law, Dip CNM
Sarah Law is a Certified Naturopathic Nutritionist and Functional Practitioner specialising in hormonal health, gut health, and evidence-based nutrition. She holds a Diploma in Naturopathic Nutrition from the College of Naturopathic Medicine (CNM, London) and is a Certified Functional Health Coach. Sarah combines naturopathic principles with modern functional nutrition science to help her clients make informed health decisions.
About the Author: Ben Law
Ben Law is the founder of Love Life Supplements and host of the Optimised Health Show. He is a qualified Advanced Dietary Supplement Advisor and Primal Blueprint Certified Expert, and has spent 14 years building transparent, research-led formulations manufactured to GMP and BRC standards. He wrote this guide from the published positions of the NIH, NHS, FSA, BfR and other regulators, the clinical trial literature and our own label.
KSM-66, Sensoril and Shoden are trademarks of their respective owners. Learn more about Ben.
References
- NIH Office of Dietary Supplements. Ashwagandha: is it helpful for stress, anxiety, or sleep? Fact sheet for health professionals. NIH ODS
- Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment. Draft minutes of the 8th September 2026 COT meeting (item: third draft statement on the safety of ashwagandha, TOX/2026/30). GOV.UK
- Which? Ashwagandha: stress buster or health risk? (1 June 2026), quoting the Food Standards Agency. which.co.uk
- NHS. Herbal medicines and complementary therapies. NHS
- German Federal Institute for Risk Assessment (BfR). Ashwagandha: food supplements with potential health risks. Communication 39/2024, 10 September 2024. bfr.bund.de
- Chandrasekhar K, Kapoor J, Anishetty S. 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 J Psychol Med. 2012;34(3):255-262. PubMed
- Lopresti AL, Smith SJ, Malvi H, Kodgule R. An investigation into the stress-relieving and pharmacological actions of an ashwagandha (Withania somnifera) extract: a randomized, double-blind, placebo-controlled study. Medicine (Baltimore). 2019;98(37):e17186. PubMed
- Verma N, Gupta SK, Tiwari S, Mishra AK. Safety of ashwagandha root extract: a randomized, placebo-controlled, study in healthy volunteers. Complement Ther Med. 2021;57:102642. PubMed
- Björnsson HK, Björnsson ES, Avula B, 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. PubMed
- Philips CA, Valsan A, Theruvath AH, et al. Ashwagandha-induced liver injury: a case series from India and literature review. Hepatol Commun. 2023;7(10):e0270. PubMed
- Ireland PJ, Hardy T, Burt AD, Donnelly MC. Drug-induced hepatocellular injury due to herbal supplement ashwagandha. J R Coll Physicians Edinb. 2021;51(4):363-365. PubMed
- Lubarska M, Hałasiński P, Hryhorowicz S, et al. Liver dangers of herbal products: a case report of ashwagandha-induced liver injury. Int J Environ Res Public Health. 2023;20(5):3921. PubMed
- Sharma AK, Basu I, Singh S. Efficacy and safety of ashwagandha root extract in subclinical hypothyroid patients: a double-blind, randomized placebo-controlled trial. J Altern Complement Med. 2018;24(3):243-248. PubMed
- NutraIngredients. Timeline: will authorities de-throne the king of herbs? (6 July 2026). nutraingredients.com
- Salve J, Pate S, Debnath K, Langade D. Adaptogenic and anxiolytic effects of ashwagandha root extract in healthy adults: a double-blind, randomized, placebo-controlled clinical study. Cureus. 2019;11(12):e6466. PubMed
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