Coumestrol is one of the major phytoestrogens, which is abundant in soybeans, legumes, and spinach. It competitively binds the estrogen receptors ERα and ERβ. Besides coumestrol is an endogenous antagonist of the human pregnane X receptor. It is known, that antagonizing the action of the human nuclear xenobiotic receptor pregnane X receptor (PXR) may have important clinical implications in preventing drug-drug interactions and improving therapeutic efficacy. Coumestrol epigenetically suppresses cancer cell proliferation, due to its inhibition of natural haspin kinase. Coumestrol exhibits broad anti-cancer effects against skin melanoma, lung cancer, breast cancer and some others cancer cell growth. Besides, was also shown the beneficial effects of coumestrol in various biological processes including, neuroprotective effects on the nervous system, and the function of the female reproductive system. However, the experiments for male rodents have strongly suggested a deleterious effect of oral, low concentration phytoestrogen content in adult male diets.