Withania somnifera and Trigonella foenum-graecum as ingredients of testosterone-boosting supplements: Possible clinical implications.

This narrative review provides an overview of scientific studies on dietary supplements that may affect circulating testosterone (T) levels to explore which substances are scientifically proven to increase T concentration. We also review the scientific literature for their potential mechanisms and laboratory test changes triggered by their use. Based on the analysis of existing data on substances used to increase endogenous T levels, especially double-blind placebo-controlled randomized clinical trials, we selected 2 herbal extracts with the best documented positive effects on T levels, Withania somnifera root and root extracts/leaves and seed extracts of Trigonella foenum-graecum. Although these substances have different postulated mechanisms of action, both significantly increase T levels in men. Withania somnifera may inhibit the effects of cortisol and prolactin on the hypothalamic-pituitary-gonadal axis and directly affect the hypothalamus. Trigonella foenum-graecum seeds contain the active substance diosgenin, which is a precursor for sex hormone synthesis in gonads.