A halogenated derivative of 17-alpha-methyltestosterone. Similar to testosterone, fluoxymesterone binds to and activates specific nuclear receptors, resulting in an increase in protein anabolism, a decrease in amino acid catabolism, and retention of nitrogen, potassium, and phosphorus. This agent also may competitively inhibit prolactin receptors and estrogen receptors, thereby inhibiting the growth of hormone-dependent tumor lines. Fluoxymesterone is approximately five times more potent than methyltestosterone. (NCI04)

An anabolic steroid that has been used in the treatment of male HYPOGONADISM, delayed puberty in males, and in the treatment of breast neoplasms in women.