Quick answer: ashwagandha (Withania somnifera) root extract has been studied in several small randomised trials for stress and sleep, with modest positive results. There is no meaningful human research showing that liposomal ashwagandha works better than standard extracts. Ashwagandha is not for everyone: rare liver injury has been reported, it can affect thyroid hormone levels, and it should be avoided in pregnancy.
What ashwagandha is
Ashwagandha is a shrub used for centuries in Ayurvedic medicine, where it is classed as an adaptogen, a herb thought to help the body cope with stress. Supplements are usually made from the root, sometimes with leaves, and are standardised to compounds called withanolides.
What the research shows
- Stress and anxiety: several small randomised controlled trials, typically using 240 to 600 mg a day of root extract for 6 to 8 weeks, reported lower stress scores and, in some, lower cortisol compared with placebo.
- Sleep: some trials and a meta-analysis suggest small improvements in sleep quality, mainly in people with insomnia.
- Exercise and other uses: studies on strength, testosterone and other outcomes are small and inconsistent.
Limitations: most studies are short, small, use different branded extracts and are often funded by manufacturers. Long-term effects are not well studied.
Is liposomal ashwagandha better?
The trials above used standard capsules of standardised root extract. We found no strong independent evidence that a liposomal format improves the effects of ashwagandha. Liposomal delivery makes the most sense for specific poorly absorbed nutrients (see Liposomal vs Regular); for ashwagandha, product standardisation and dose matter more than the delivery format.
Safety warnings
- Liver injury: a number of cases of liver injury linked to ashwagandha supplements have been reported in medical literature. Stop and see a doctor if you notice yellowing of the skin or eyes, dark urine, itching or abdominal pain. Avoid ashwagandha if you have liver disease.
- Thyroid: ashwagandha may increase thyroid hormone levels. People with thyroid conditions or taking thyroid medication should talk to their doctor first.
- Pregnancy and breastfeeding: avoid. Traditional sources and some regulators warn against use in pregnancy.
- Autoimmune conditions: it may stimulate the immune system; ask your doctor if you have an autoimmune disease or take immunosuppressants.
- Sedatives and sleep medications: may add to drowsiness.
- Diabetes and blood pressure medications: may lower blood sugar and blood pressure.
- Surgery: stop at least two weeks before, as it may add to anaesthesia effects.
- Regulatory caution: some European food safety authorities have reviewed ashwagandha’s safety in recent years, and Denmark moved to restrict it in supplements.
How to choose an ashwagandha product in Canada
- Choose a licensed product with an NPN (how to check) and read the approved uses and warnings.
- Check the plant part (root is the most studied) and the standardisation (percent withanolides).
- Stick to label doses and durations.
- Review your medications and conditions with a pharmacist.
Non-supplement ways to manage stress
Regular physical activity, consistent sleep habits, limiting caffeine and alcohol, time outdoors and talking to someone you trust all have strong evidence for stress and sleep. If stress or anxiety affects your daily life, speak with your doctor or a mental health professional.
Frequently asked questions
How long does ashwagandha take to work?
Studies typically measured effects after 6 to 8 weeks.
Can I take ashwagandha every day long term?
Long-term safety has not been well studied. Follow the duration on the label and check in with a health professional.
Does ashwagandha interact with antidepressants?
Possible interactions with medications affecting mood and sleep have not been well studied. Ask your pharmacist before combining.
Sources
- National Center for Complementary and Integrative Health (NIH). Ashwagandha fact sheet.
- National Institutes of Health, Office of Dietary Supplements. Ashwagandha fact sheet for health professionals.
- NIH LiverTox database. Ashwagandha.
- Health Canada. Licensed Natural Health Products Database.
This article is for general information only and is not medical advice. See our medical disclaimer.
