Herb library · Herb · Withania somnifera
Ashwagandha
An evergreen shrub of India, Africa, and the Middle East, sold as root, leaf, or root-and-leaf extracts. Some preparations may help with sleeplessness and stress; the evidence on anxiety is unclear, and it carries more safety cautions than most herbs here.
Traditional use
Ashwagandha, also called Indian ginseng, has been used as a medicinal plant for thousands of years, especially in traditional Ayurvedic medicine. Today its supplements are promoted for stress and anxiety, sleep, male infertility, and athletic performance.
What studies show
- Limited
Insomnia and stress: research shows some ashwagandha preparations may be effective for insomnia and stress. NCCIH notes that many trials had small sample sizes and used a variety of preparations, so results may not carry over from one product to another.
- Insufficient
Anxiety: the evidence about its effects on anxiety is unclear.
- Limited
Male fertility: some limited evidence suggests taking ashwagandha for 2 to 4 months may raise testosterone levels and sperm quality.
- Insufficient
Other uses: there is not enough evidence to say whether it helps with asthma, athletic performance, thinking and memory, diabetes, menopause, or female infertility, and not enough high-quality evidence for COVID-19.
Be careful of
Cautions
- AmountAshwagandha may be safe for short-term use, up to 3 months; there is not enough information to judge long-term safety. It can cause drowsiness, stomach upset, diarrhea, and vomiting.
- ConditionRare cases of liver injury have been linked to ashwagandha supplements.
- ConditionNot recommended for people about to have surgery, or for people with autoimmune or thyroid disorders. Because it may raise testosterone, people with hormone-sensitive prostate cancer should avoid it.
- InteractionIt might interact with medicines for diabetes and high blood pressure, immunosuppressants, sedatives, anti-seizure medicines, and thyroid hormone medicines.
- PregnancyAvoid during pregnancy, and do not use while breastfeeding.
- Ask a clinicianTalk with a clinician or pharmacist before using this if you take prescription medicines, are pregnant or breastfeeding, or have a medical condition.
From the old books
What herbals and dispensaries of the past printed. History, in their words.
“It is said that the root smells like a horse whence the Sanskrit name asvangandhá. The specimen in my possession however has scarcely any odour or taste.”
Sources
- Ashwagandha: Usefulness and Safety (opens in a new tab) · NCCIH · read September 15, 2026
Reviewed September 15, 2026.