Testosterone propionate is a male sexual hormone with pronounced, mainly androgenic action, possessing the biological and therapeutic properties of the natural hormone. In a healthy male organism, androgens are formed by the testes and adrenal cortex. It is normally produced in women in small physiological quantities. In addition to the specific action that determines the sexual characteristics of the individual, it also has a general anabolic action, manifested in enhancement of protein synthesis. Under the effect of testosterone, body weight increases and urea excretion is reduced. High doses suppress the production of hypophyseal gonadotropin, while low doses stimulate it. It has an antitumor effect on mammary gland metastases.