Letrozole

Letrozole is an anti-estrogen of the Aromatase Inhibitor (AI) family which holds the purpose of blocking the aromatase enzyme, which is in turn responsible for the production of estrogen. Letrozole is one of the most potent and powerfully effective of all AIs. While intended for breast cancer treatment, it has found a welcomed home among anabolic steroid users and is one of the most commonly used anti-estrogens among steroid users to combat possible estrogenic related side effects. It is so effective as an anti-estrogen in this regard that many steroid users have effectively reversed gynecomastia symptoms with the use of Letrozole.