combination of 4 of testosterones. The presence of the acetate ester allows the testosterone to display a rapid initial physiological response. The other four esters, which release at slower rates, prolong the physiological response with a relatively flat absorption curve over the duation of the injection life-cycle. Testosterone is a male sexual hormone with pronounced, mainly androgenic action, possessing the biological and therapeutic properties of the natural hormone. It is normally produced in women in small physiological quantities. In addition to the specific action that determines the sexual characteristics of the individual, testosterone 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.