Research has shown that ashwagandha may have beneficial effects on athletic performance and may be a worthwhile supplement for athletes. One analysis of research included 12 studies in men and women who took ashwagandha doses between 120 mg and 1,250 mg per day. The results suggest the herb may enhance physical performance, including strength and oxygen use during exercise

Many people take ashwagandha to promote restful sleep, and some evidence suggests it may help with sleep issues. For example, a study in 50 adults ages 65–80 found that taking 600 mg of ashwagandha root per day for 12 weeks significantly improved sleep quality and mental alertness upon waking compared with a placebo treatment.

Ashwagandha supplements have been shown in some studies to benefit male fertility and increase testosterone levels. In one study, 43 overweight men ages 40–70 who had mild fatigue took tablets containing ashwagandha extract or a placebo daily for 8 weeks. The ashwagandha treatment was associated with an 18% greater increase in DHEA-S, a sex hormone involved in testosterone production. Participants who took the herb also had a 14.7% greater increase in testosterone than those who took the placebo.

Taking ashwagandha may benefit cognitive function. One review that included five clinical studies noted there was early evidence that ashwagandha could improve cognitive functioning in certain populations, including older adults with mild cognitive impairment and people with schizophrenia.