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Ashwagandha
Ashwagandha — what the European monograph actually supports, what it is not for, the form and how long it is meant to be used, side effects, and the 4 medicine interactions documented for it.
This is a reference page, not a diagnosis and not a prescription. Herbal products are real pharmacology: they have effects, side effects and interactions with medicines. Tell your doctor and your pharmacist everything you take, including teas and supplements, and never stop or change a prescribed medicine because of anything you read here.
What it is
Withania somnifera (L.) Dunal — root
Local names across the region this site serves: ashwagandha (ET, FI) · ашваганда (RU).
Grouped here under Mind, mood and fatigue. Regulatory position: No EU herbal monograph — sold as a food supplement.
What the evidence supports
The registered indication: Nothing a European regulator has assessed. It is marketed for stress, sleep, testosterone and athletic performance.
Ashwagandha went from obscure to ubiquitous in a few years, and it is the clearest example on this page of popularity running ahead of assessment. There is no European Union herbal monograph for it, which means no EU regulator has agreed a standard preparation, a standard strength, a standard duration or an accepted indication. What has accumulated instead is a safety file: cases of liver injury following ashwagandha products are recorded in the NIH LiverTox database, typically as a hepatitis-like picture appearing some weeks after starting and resolving after stopping, occasionally with jaundice and prolonged recovery. At least one Nordic food-safety authority has acted on a national risk assessment to keep it out of food supplements. The human trials that supplement marketing quotes are mostly small, short and conducted by parties with an interest in the answer.
D — Popular claim unsupported, or safety dominates The better trials are negative, or the substance appears in the literature mainly for the harm it has caused.
What it is not for
Anxiety disorders, thyroid disease, infertility and low testosterone — all of which are diagnosable conditions with real treatments and none of which should be self-managed from a capsule bottle.
Form, strength and how long
Root powder and standardised root extracts in capsules; some products use leaf material, which has a different and less studied chemistry.
Duration. No agreed duration exists. Given the liver signal, indefinite daily use is the pattern most worth avoiding.
No gram figure appears on this page on purpose. The plant part, the extraction solvent and the drug-to-extract ratio together define a preparation, and a number taken from one does not describe another. The reasoning is set out on the hub; the amount that applies to you is the one printed on the pack you are holding, and a pharmacist will read it with you.
Side effects
Stomach upset, loose stools and drowsiness are the common reports. The one to know is liver injury: dark urine, yellowing of the eyes or skin, itching, unusual tiredness, pain under the right ribs. Stop and seek medical care if any of those appear.
Who should avoid it
Avoid in pregnancy — the plant has documented traditional use as an abortifacient — and while breastfeeding. Avoid with existing liver disease.
Interactions with medicines
| Medicine or substance | What is described |
|---|---|
| Levothyroxine and thyroid treatment | Ashwagandha has been reported to raise thyroid hormone levels. With an existing thyroid condition, or on levothyroxine, that is a real and checkable concern rather than a theoretical one. |
| Sleeping tablets, benzodiazepines and sedating antihistamines | Additive drowsiness with sedatives, sleeping tablets and alcohol. |
| Immunosuppressants and transplant medicines | It is marketed as immune-modulating, which is working against the purpose of immunosuppressant therapy. Transplant and autoimmune patients should not add it without their team's agreement. |
| Anything else that stresses the liver | Stacking it with anything else carrying a liver signal — other implicated botanicals, heavy alcohol, medicines known to affect liver enzymes — compounds the one serious risk this plant has. |
The reverse view — start from the medicine rather than the plant — is in the medicine, food and alcohol interactions reference, and summarised for every herb on this site.
Sources: LiverTox: Clinical and Research Information on Drug-Induced Liver Injury (NIDDK, National Institutes of Health) · NIH National Center for Complementary and Integrative Health — herb fact sheets · checked 2026-09-06
Frequently asked questions
What is ashwagandha used for?
Nothing a European regulator has assessed. It is marketed for stress, sleep, testosterone and athletic performance. Ashwagandha went from obscure to ubiquitous in a few years, and it is the clearest example on this page of popularity running ahead of assessment. There is no European Union herbal monograph for it, which means no EU regulator has agreed a standard preparation, a standard strength, a standard duration or an accepted indication. What has accumulated instead is a safety file: cases of liver injury following ashwagandha products are recorded in the NIH LiverTox database, typically as a hepatitis-like picture appearing some weeks after starting and resolving after stopping, occasionally with jaundice and prolonged recovery. At least one Nordic food-safety authority has acted on a national risk assessment to keep it out of food supplements. The human trials that supplement marketing quotes are mostly small, short and conducted by parties with an interest in the answer.
Does ashwagandha work?
Graded D here: The better trials are negative, or the substance appears in the literature mainly for the harm it has caused. Anxiety disorders, thyroid disease, infertility and low testosterone — all of which are diagnosable conditions with real treatments and none of which should be self-managed from a capsule bottle.
How much ashwagandha should I take?
This reference does not print gram figures, because they do not transfer between preparations of different extract strength. What can be said honestly is the form and the duration: Root powder and standardised root extracts in capsules; some products use leaf material, which has a different and less studied chemistry. No agreed duration exists. Given the liver signal, indefinite daily use is the pattern most worth avoiding.
What are the side effects of ashwagandha?
Stomach upset, loose stools and drowsiness are the common reports. The one to know is liver injury: dark urine, yellowing of the eyes or skin, itching, unusual tiredness, pain under the right ribs. Stop and seek medical care if any of those appear.
Does ashwagandha interact with medicines?
Yes — documented for Levothyroxine, Sedatives, Immunosuppressants, Liver load. Each one is described on this page, with a link to the medicine-side reference where one exists.
Others in mind, mood and fatigue
St John's wort
Mild to moderate depressive episodes, for particular standardised dry extracts; traditional-use preparations are also registered for temporary mental exhaustion and, externally, for minor wounds and skin inflammation.
Ginkgo
Improvement of cognitive impairment and of quality of life in mild dementia, for a specific standardised leaf dry extract used under medical supervision.
Ginseng (Panax)
Symptoms of asthenia such as fatigue and weakness.
Rhodiola (roseroot)
Temporary relief of symptoms of stress, such as fatigue and a sensation of weakness.
Keep the whole list in one place
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