Ashwagandha has shown mixed effects on hormone health measures such as cortisol, testosterone, estrogen, luteinizing hormone, follicle-stimulating hormone, prolactin, and thyroid hormones in human studies. In animal models, ashwagandha appears to reduce the stress-related increase in corticosteroids in serum, and at the higher doses of supplementation (though still within the doses humans use), to fully normalize cortisol to control levels.[1][2][3] The cortisol reductions seen in chronically stressed adults with ashwagandha (300–500 mg over 60–90 days) tend to be in the range of 20%–50% from baseline values, with more of an effect seen in people who self-report high levels of stress.[4][5]
Ashwagandha’s effects on hormones are not limited to cortisol. Preliminary evidence suggests that 500–600 mg of ashwagandha root extract per day may increase testosterone levels in men when taken over 3–6 months. Improvements in testosterone levels, luteinizing hormone, follicle-stimulating hormone, sperm quality parameters, quality of life, and sexual functioning have been seen with ashwagandha use.[6][7][8][9][10][11] Effects on testosterone are more pronounced in men with infertility and low testosterone levels, though ashwagandha may also boost testosterone levels in healthy men as well.[12][13][8][14][9][5] When supplemented by infertile men, ashwagandha enhanced seminal parameters (e.g. sperm count, motility, quality, and vitality), suggesting that it may help to improve fertility. It’s possible that increased testicular and sperm cell antioxidant status may be partially responsible for these effects.[5][9][11][10]
Ashwagandha may also have beneficial effects on hormone health in women. Though current evidence suggests these beneficial effects are less pronounced than those seen in men, there still isn’t enough evidence to say this conclusively. Ashwagandha apparently also improves sexual function in women, but it’s not clear yet whether subjective well being is similarly enhanced.[15] One study did find that ashwagandha use in women with menopause increased estrogen while simultaneously lowering follicle-stimulating hormone and luteinizing hormone levels to produce an overall improvement toward menopausal symptom related quality of life.[16]