A Randomized, Double-Blind, Placebo-Controlled, Crossover Study Examining the Hormonal and Vitality Effects of Ashwagandha (Withania somnifera) in Aging, Overweight Males

Researchers gave 43 overweight men aged 40 to 70 either ashwagandha or a placebo, an inactive look-alike treatment, for eight weeks. Each man tried both treatments in a crossover study, meaning he received the treatments at different times. Blood tests measured hormones, chemical messengers in the body, including testosterone, DHEA-S, estradiol, and cortisol. Ashwagandha raised testosterone, DHEA-S, and estradiol more than the placebo, but it did not clearly improve reported vitality or lower cortisol.

What this means for you: This suggests a possible short-term hormone effect in overweight middle-aged and older men, not a proven vitality or longevity benefit. The study was small and brief, so it is not strong enough reason to buy ashwagandha for general health.