This post cycle substance has gained much popularity among athletes due to its reputed ability to act as a gonadotropic stimulant and estrogen blocker. Clomidex Gonadotropil, the active ingredient in Omnifen, enhances testosterone levels by acting on the pituitary gland rather than the testes themselves. This pituitary stimulation causes an increased production of gonadotropins, particularly luteinizing hormone, which then activates the testes to increase endogenous testosterone levels. Typically taken at the end of a cycle, omifen is preferred over HCG because of its ability to gradually restore the testicular axis to normal levels after a cycle. The spike of testosterone noted after administration of HCG may be counterproductive because of its excessive magnitude. This huge spike from HCG actually triggers the pituitary to again stop making these necessary gonadotropins.