Anti-estrogens

Most kinds of anti-estrogens have the below biological actions:

they include SERMS (often used in breast cancer treatment and to treat gynecomastia, only mess with certain estrogen receptors),

aromatase inhibitors (prevent testosterone from being converted to estrogen), and

estrogen receptor inhibitors (inhibit the estrogen receptor body-wide).

The only notable exceptions to these mechanisms are GnRH blockers (which lower estrogen in those with ovaries) and the medicine Danazol, which both inhibits production of GnRH and blocks FSH and LH in those with ovaries, reducing estrogen production in those organs. Danazol also has mild androgenic effects and possibly binds to androgen and proestrogen receptors.

Almost all of the above medications are used to treat breast cancer.

Aromatase inhibitors are used as a last resort (or with conjunction with SERMs) in the treatment of some estrogen dependent disorders.

Some SERMs are used in the treatment of gynecomastia, as the majority of them prevent estrogen from being used in the breasts.

Letrozole (an estrogen inhibitor) has been shown to prevent growth plate fusion, so doctors sometimes use it in conjunction with growth hormone to help short children and teens gain height. It elevates LH but does not increase FSH.

Anastrozole has been used for effective gynecomastia treatment, however, how it does this is unknown, since it is an aromatase inhibitor.

List of medications/compounds
SERMs: Include compounds like Raloxifene, Tamoxifene, Afimoxifene