Biotin (vitamin B7 or vitamin H) is one of the B complex vitamins. It is commonly found in hair, nail and skin supplements. High doses of biotin may affect some men's health test results, including testosterone, estradiol, cortisol, sex hormone binding globulin (SHBG), and dehydroepiandrosterone sulfate (DHEA-S). It is recommended that biotin supplements are avoided at least 72 hours before sample collection.