Scientists tested whether an herb called ashwagandha helps young men who don't work out build muscle or get stronger, but they only studied men ages 18-50 for 8 weeks, so we don't know if it works for women, older adults, athletes, or if taking it longer makes any difference.

Taking ashwagandha supplements (300mg twice daily for 8 weeks) helps young men build more leg muscle strength during weight training compared to taking a placebo pill - about 14.5 kg more strength gain versus 9.8 kg with placebo.

Taking ashwagandha supplements (300mg twice daily for 8 weeks) while doing weight training makes your arm muscles and chest grow bigger compared to just doing weight training with a fake pill (placebo).

Taking ashwagandha supplements (300mg twice a day for 2 months) may boost testosterone levels in young men who lift weights, according to one study that found a much bigger increase compared to a placebo pill.

Taking ashwagandha supplements (300mg twice daily for 2 months) was safe for healthy young men who exercised - none of them had any serious side effects and everyone thought it was either good or excellent to take.

Taking ashwagandha supplements (300mg twice daily) for 8 weeks while doing weight training may help men lose more body fat - about 3.5% versus 1.5% with a placebo pill.