A genuine stress-study herb with a real, if uncommon, liver and thyroid signal. — Withania somnifera
remedyAshwagandha Withania somnifera — hand-drawn plate, stylised. Not for identification — use a field guide and verify with a second source before eating any wild plant.
Ashwagandha (Withania somnifera) has randomised trial evidence for reducing perceived stress and anxiety scores, with small trials also showing improvements in sleep and in strength measures. It is the best-studied of the herbs sold as adaptogens, and unlike most of them the trials are real.
What the effect is worth. Small-to-moderate improvements in questionnaire-based stress measures, in trials that are often small, short and sometimes industry-linked. That is a real but modest claim, and it is not the same as treating an anxiety disorder.
The two safety signals that matter.
Liver injury. Cases of ashwagandha-associated hepatotoxicity have been reported, and it is now a recognised cause of herbal liver injury. Uncommon, but real, and it means unexplained liver symptoms on ashwagandha need attention.
Thyroid effects. Ashwagandha can raise thyroid hormone levels, which is a concern for anyone with hyperthyroidism or on thyroid medication, and occasionally useful information for someone with subclinical hypothyroidism — under supervision.
Growing it here is not practical — it wants a hot, dry climate and a long season. It is a buy-it herb in this climate, and given the liver signal it is worth buying from a supplier who can state the species and the part.
What the studies found
Meta-Analysis2026Complementary therapies in medicine
Effects of ashwagandha (Withania somnifera) on mental health in adults: A systematic review and dose-response meta-analysis of randomized controlled trials.
Current evidence suggests that ashwagandha supplementation holds promising potential in alleviating symptoms of stress, anxiety, and depression.
Safety and efficacy of Withania somnifera for anxiety and insomnia: Systematic review and meta-analysis.
While W. somnifera extracts yielded promising results, further research with larger sample sizes is needed to confirm its effects on anxiety and insomnia.
Does Ashwagandha supplementation have a beneficial effect on the management of anxiety and stress? A systematic review and meta-analysis of randomized controlled trials.
However, further high-quality studies are needed to firmly establish the clinical efficacy of the plant.
Medicinal herbs for the treatment of anxiety: A systematic review and network meta-analysis.
However, these results should be considered preliminary because of the unconvincing sample sizes, together with the potential effectiveness of placebos.
| | |
|---|---|
| Life | Woody shrub, tropical/subtropical dry |
| Reality here | Not practical in zone 6a — buy it |
| Container | Possible in a greenhouse; a long hot season is needed |
| Note | The root is the part usually used |
There is no useful home cultivation here. This entry exists so the evidence and the safety signals are recorded alongside the rest of the pharmacopoeia.
Preparation
Root powder — 1-2 teaspoons in warm milk or water. The traditional form.
Capsules / standardised extract — what most trials used; typically 300-600 mg daily of a standardised extract.
Tincture — root in alcohol.
Cycle it — the traditional use is in courses rather than indefinitely, which is also prudent given the liver reports.
Do not combine with thyroid medication or sedatives without advice.
Cautions and interactions
Ashwagandha has been associated with liver injury in reported cases. Stop and get assessed if liver symptoms appear.
It can raise thyroid hormone levels — avoid in hyperthyroidism or with thyroid medication without advice.
Avoid in pregnancy — traditionally avoided as a uterine stimulant.
Adds to sedation with sedatives and alcohol.
May affect blood sugar and blood pressure.
Not a treatment for an anxiety disorder.
When this is not a self-care problem — get help
Jaundice, dark urine, nausea or right-upper abdominal pain while taking ashwagandha — stop and get assessed.
Palpitations, unexplained weight loss, heat intolerance or tremor — possible thyroid effect; get assessed.
Any suicidal thought — get help now. In the US, call or text 988.
Known interactions
Additive with sedatives; possible interaction with thyroid medication, blood-sugar-lowering drugs and antihypertensives.
Effects of ashwagandha (Withania somnifera) on mental health in adults: A systematic review and dose-response meta-analysis of randomized controlled trials. Complementary therapies in medicine 2026; doi:10.1016/j.ctim.2026.103325 PubMed 41644067
Hormonal Modulation with Withania somnifera: Systematic Review and Meta-Analysis of Randomized-controlled Trials. Planta medica 2026; doi:10.1055/a-2802-8363 PubMed 41740946
Effects of Ashwagandha (Withania Somnifera) on stress and anxiety: A systematic review and meta-analysis. Explore (New York, N.Y.) 2024; doi:10.1016/j.explore.2024.103062 PubMed 39348746
Safety and efficacy of Withania somnifera for anxiety and insomnia: Systematic review and meta-analysis. Human psychopharmacology 2024; doi:10.1002/hup.2911 PubMed 39083548
Does Ashwagandha supplementation have a beneficial effect on the management of anxiety and stress? A systematic review and meta-analysis of randomized controlled trials. Phytotherapy research : PTR 2022; doi:10.1002/ptr.7598 PubMed 36017529
Medicinal herbs for the treatment of anxiety: A systematic review and network meta-analysis. Pharmacological research 2022; doi:10.1016/j.phrs.2022.106204 PubMed 35378276