Clomid (Fertomid) is very popular anti-estrogen, used for improving recovery of natural testosterone production after a steroid cycle, improving testosterone production of endurance athletes, Clomid is also effective in reducing risk of gynecomastia during a cycle when using steroids. While it has been claimed that Clomid stimulates production of LH and therefore testosterone, in fact Clomid activity is achieved not by stimulation of the hypothalamus and pituitary, but by blocking their inhibition by estrogen.