Ashwagandha
Ashwagandha (Withania somnifera) is an herb used in Ayurveda, the traditional medicine of India. Its root has a horsey smell (in Sanskrit, ashva means “horse” and gandha means “smell”) and is said to confer the strength and virility of a horse. Various parts of the plant are used, but the most common in supplements is an extract of its roots.
A number of studies suggest that it has anxiolytic (anti-anxiety) effects; studies are mostly supportive of a notable effect of ashwagandha for this purpose, and it seems to reduce cortisol levels. However, more research is needed before we can have a great deal of confidence in it or know the optimal dose. Ashwagandha may also be able to reduce insomnia, fatigue, and the symptoms of depression, but it hasn't been well-researched for these purposes.
It may increase power output in untrained subjects during resistance exercise and anaerobic running, but this observation is based on a small amount of research and more is needed. It may lead to small reductions in blood glucose, blood pressure, and LDL-cholesterol, while slightly increasing HDL-cholesterol. Additionally, it may modestly increase testosterone and sperm quality in infertile men.
