Like many other aromatase inhibitors (AIs) used in conjunction with anabolic steroids, Letrozole was initially developed for the medical treatment of breast cancer in post-menopausal women. By blocking the production of estrogen in the body, Letrozole has been found to effectively reduce the size and progression of breast tumors. In the bodybuilding community, Letrozole has become popular for its ability to reduce estrogen levels and minimize the side effects of anabolic steroids such as water retention and gynecomastia.
The reason it is only used in women of such an age is due to its powerful estrogen blocking ability which would have serious health implications for pre-menopausal women, but for male steroid users it is this trait that makes AIs like Letrozole so appealing as we aim to combat the adverse effects of estrogen when using aromatizing steroids.
Letrozole can lower your overall estrogen levels because it blocks the aromatase enzyme. This contrasts with the other popular category of estrogen control drugs for steroids users, SERMs, which only target very specific areas of the body. This allows Letrozole to combat a wider range of estrogenic side effects caused by steroids, with the two main ones being gynecomastia and water retention.
This will also help prevent the high blood pressure that can come along when excess water retention is not addressed.