What it is
Ashwagandha is a small shrub in the nightshade family, central to Ayurvedic medicine, where it is classed as a "rasayana" or tonic. The root is the traditional part; leaf extracts contain more withaferin A, and India restricted leaf use in 2026.
What the research says
Stress
ModerateSome preparations may reduce stress scores in trials of up to about three months. Trials are small and use different extracts.
Sleep
MixedSome preparations may help with insomnia.
Anxiety
LimitedEvidence is unclear.
Amounts used in studies
Trials mostly used 250–600 mg a day of root extract for 6–12 weeks. Long-term safety is not established.
Who should avoid it
- Pregnancy and breastfeeding.
- Thyroid disorders and autoimmune diseases.
- Hormone-sensitive prostate cancer (it may raise testosterone).
- The weeks before surgery.
- Liver disease.
Medicines to watch
- Thyroid hormone medicine.
- Sedatives and sleep medicines, anti-seizure medicines.
- Immunosuppressants.
- Diabetes and blood-pressure medicines.
Warning signs. Stop and see a doctor if you notice yellowing of the skin or eyes, dark urine, itching or unusual tiredness.
What to look for when buying
- Insist on root-only extract with a stated withanolide percentage.
- Ask the supplier to confirm no leaf material is included.
Common questions
Why is it banned in some countries?
Denmark’s food authority found too little data to set a safe intake and raised concerns about hormones and the liver. Others in Europe are reviewing it. Industry groups dispute the findings; the review is ongoing.
How long can I take it?
Most safety data covers up to about three months. Take a break and review with your doctor after that.
Read next
Sources
Last reviewed 19 October 2026 by Spicewell editorial team. How we write our guides
This guide is general information, not medical advice. Speak to a doctor or pharmacist before starting any supplement, especially if you are pregnant, breastfeeding, under 18 or taking medication.