Ashwagandha for men rests on limited evidence. The US National Institutes of Health cites limited evidence that two to four months of use may raise testosterone and sperm quality, but the trials are small, and a placebo-controlled trial in men aged 40 to 70 found no difference in fatigue, vigor or sexual well-being. The main risks are rare liver injury, possible thyroid effects and medicine interactions.
That matters because ashwagandha is widely sold to men as a testosterone, stress or sleep product. This guide covers what the trials measured, which side effects are reported, who should avoid it and where regulators in Denmark, the UK, Australia and the US stood in October 2026.
What is ashwagandha, and why is it marketed to men?
Ashwagandha (Withania somnifera) is an evergreen shrub in the nightshade family, according to the Danish Veterinary and Food Administration. The US National Center for Complementary and Integrative Health (NCCIH) says supplements typically contain root, leaf or combined extracts and are often promoted for stress and anxiety, sleep, male infertility and athletic performance.
Withanolides are bioactive plant compounds in ashwagandha with various reported effects. The Therapeutic Goods Administration (TGA) notes that their concentration varies with the plant part used and that the extraction method also changes the final product.
So two bottles labeled ashwagandha may not be chemically alike, which matters whenever a study is quoted to sell a different product.
Does ashwagandha increase testosterone?
Ashwagandha may raise testosterone modestly in some men, but the evidence is thin. NCCIH describes only "some limited evidence" that taking it for two to four months may increase testosterone levels and sperm quality.
The trial most relevant to men in midlife is a 2019 crossover study in overweight men aged 40 to 70 with mild fatigue. A crossover trial gives each participant both the active product and the placebo, in random order. Fifty-seven men enrolled and 43 completed all 16 weeks.
Saliva testosterone rose 14.7% more with ashwagandha than with placebo. Fatigue, vigor and sexual well-being improved over time, with no statistically significant difference between ashwagandha and placebo. The company that supplied the extract funded the study.
A 2026 meta-analysis of 23 randomized trials with 1,706 participants estimated that ashwagandha raised testosterone in men by an average of 57.43 ng/dL compared with placebo. A meta-analysis pools results from several studies. The authors noted heterogeneity between trials and called for further standardized research.
If your report uses nmol/L rather than ng/dL, our guide to testosterone levels by age explains the units. A higher number on a report is not the same as treating testosterone deficiency, which needs a diagnosis first.
Why the ashwagandha evidence is weaker than the marketing
Ashwagandha research for men has recurring limits: small samples, short follow-up, hormone levels used as outcomes instead of symptoms, and extracts that may not match the product on sale.
The 2019 trial measured testosterone in saliva, not blood, and enrolled men with mild fatigue rather than diagnosed low testosterone. Results from one standardized extract cannot be transferred to a gummy, tea or blend with a different plant part and dose.
Long-term safety is also unknown. NCCIH says ashwagandha may be safe in the short term, up to three months, and that there is not enough information to reach conclusions about longer use. Our review of testosterone booster evidence explains why an ingredient study does not prove a retail product works.
What are the side effects of ashwagandha?
NCCIH lists drowsiness, stomach upset, diarrhea and vomiting as side effects of ashwagandha in some people. The TGA adds that sudden nausea, vomiting and diarrhea after taking it can be mistaken for gastroenteritis or food poisoning.
Thyroid effects are less obvious. The 2026 meta-analysis found no effect on TSH (thyroid stimulating hormone) or T3, but a modest rise in T4 of 0.61 µg/dL. T4, or thyroxine, is the main hormone released by the thyroid gland. NCCIH advises that ashwagandha is not recommended for people with thyroid disorders and may interact with thyroid hormone medicines. Our guide to thyroid tests explains what each result measures.
Can ashwagandha cause liver damage?
Ashwagandha can cause liver injury, but it appears to be rare. A case series from Iceland and the US Drug-Induced Liver Injury Network described five people who developed jaundice 2 to 12 weeks after starting ashwagandha supplements. Jaundice is yellowing of the skin and eyes. The injury was cholestatic, a pattern in which bile flow is impaired, or mixed. No patient developed liver failure, and liver tests returned to normal within 1 to 5 months in four of the five.
The TGA's July 2026 update counts 11 possible liver injury cases reported to it, with no deaths or liver transplants among Australian consumers. It also cites an Indian case series in which three people with pre-existing liver disease died after developing acute-on-chronic liver failure. The TGA concludes that the risk appears very rare, and says products containing Withania somnifera should be avoided by people with existing liver disorders.
The symptoms in the US and Icelandic cases included yellow skin or eyes, itching, nausea, unusual tiredness and abdominal discomfort. If any appear while you are taking ashwagandha, stop the product and see a doctor promptly with the label. If you feel severely ill, call 911 in the US, 999 in the UK or 000 in Australia. For what a liver panel can show, read elevated liver enzymes.
Why is ashwagandha banned in some countries?
Ashwagandha is banned from food sale in Denmark and under formal review in the UK. The positions below were checked in October 2026.
| Country | Regulator | Position in October 2026 |
|---|---|---|
| Denmark | Danish Veterinary and Food Administration | Illegal to sell as food, including supplements |
| UK | Committee on Toxicity, with the Food Standards Agency | Safety statement in draft; third draft discussed September 2026 |
| Australia | Therapeutic Goods Administration | Permitted in listed medicines; very rare liver injury warning |
| US | Food and Drug Administration | Sold as a dietary supplement without premarket approval |
Denmark's food regulator says a Technical University of Denmark risk assessment found negative effects on sex hormones and reproduction in both men and women, with possible effects on metabolism, the immune system and the central nervous system.
In the UK, the Committee on Toxicity, whose secretariat is the Food Standards Agency, discussed a third draft statement on ashwagandha safety in September 2026. The content was reserved as unpublished. Australia permits the herb in listed medicines and requires a pregnancy warning on certain preparations, according to the TGA. In the US, the FDA does not have authority to approve dietary supplements before they are marketed.
Who should not take ashwagandha?
NCCIH says ashwagandha is not recommended for people about to have surgery or for those with autoimmune or thyroid disorders. Men with hormone-sensitive prostate cancer should avoid it, because it may increase testosterone. The TGA adds people with existing liver disorders.
Medicine interactions matter too. NCCIH lists possible interactions with medicines for diabetes and high blood pressure, immunosuppressants, sedatives, anti-seizure medicines and thyroid hormone. If you take any of these, ask your prescriber or pharmacist first.
Checks before you start or continue ashwagandha
1. Name the problem you want to solve.
Write down whether you are chasing sleep, stress, training or testosterone. Each needs different evidence, and persistent symptoms deserve assessment rather than a supplement trial.
2. Identify the extract on the label.
Look for the plant part, the extract type and the stated withanolide content. If the label says only ashwagandha powder or a proprietary blend, you cannot match it to any trial. Our supplement label checklist shows what to look for.
3. Count every product that contains it.
Ashwagandha can appear in multi-ingredient sleep, stress or testosterone products. Two products can mean a double dose you did not intend.
4. Check your medicine list against the interaction list.
Bring the label and your prescriptions to a pharmacist. Diabetes, blood pressure, thyroid, seizure, immune and sedative medicines are the ones NCCIH names.
5. Know the stop signs.
Yellowing skin or eyes, itching, nausea or unusual tiredness mean stopping and seeking medical advice. Do not restart the product without that advice.
What to ask your doctor about ashwagandha
Start with your US primary care physician, UK GP or Australian GP, and bring the bottle. Ask whether your thyroid, liver or prostate history or your medicines make ashwagandha unsuitable.
If your real question is testosterone, ask whether testing is warranted. If you have surgery scheduled, tell the surgical team, given NCCIH's advice against use before surgery.
Frequently asked questions
Does ashwagandha increase testosterone?
Ashwagandha may raise testosterone modestly. A 2026 meta-analysis of 23 randomized trials estimated an average rise of 57.43 ng/dL in men compared with placebo, but trials were small and varied. A higher blood or saliva level is not proof that symptoms will improve, or that the supplement treats diagnosed testosterone deficiency.
Is ashwagandha safe to take every day?
The US National Center for Complementary and Integrative Health says ashwagandha may be safe in the short term, up to three months, and that long-term safety is unknown. It does not recommend ashwagandha for people with thyroid or autoimmune disorders or upcoming surgery, and Australia's TGA advises avoiding it with existing liver disease.
Can ashwagandha cause liver damage?
Yes, but rarely. Case reports describe jaundice appearing 2 to 12 weeks after starting ashwagandha, usually improving after stopping. Australia's TGA reports 11 possible cases and no Australian deaths. The most serious reported outcomes involved people with existing liver disease, and the TGA advises them to avoid the herb.
Why is ashwagandha banned in Denmark?
Denmark bans the sale of ashwagandha as food, including supplements. The Danish food regulator says a Technical University of Denmark risk assessment found negative effects on sex hormones and reproduction in men and women, plus possible effects on metabolism, the immune system and the central nervous system.
Does ashwagandha affect the thyroid?
Ashwagandha may affect thyroid hormones. A 2026 meta-analysis found no change in TSH or T3 but a modest rise in T4. The US National Center for Complementary and Integrative Health does not recommend it for people with thyroid disorders and warns it may interact with thyroid hormone medicines.
The short version
Ashwagandha may nudge testosterone up a little, but the trials are small and short, and the main midlife trial was funded by its supplier. Reported side effects include digestive upset and drowsiness, while liver injury is rare and most serious in people with existing liver disease. Denmark bans its sale as food and the UK is reviewing its safety. Check the label, your medicines and your health history before buying.
This article is general education, not medical advice. It does not replace your own physician.
