The strongest evidence is for stress and anxiety reduction. Multiple randomised trials have found ashwagandha root extract reduces cortisol, perceived stress, and anxiety symptoms compared to placebo. The typical studied dose is 300 to 600 milligrams of a standardised root extract daily for eight to twelve weeks.
Evidence also supports improved physical endurance, strength gains alongside resistance training, and modest testosterone increases in men. Ashwagandha is generally safe for healthy adults but should be avoided in pregnancy and by people with autoimmune conditions without medical supervision.