Tamoxifen is prescribed to treat certain types of breast cancer in women and men. It is also used to lower risk of having and developing breast in women because of a genetic predisposition. The drug is also widely used by bodybuilders, taking anabolic steroids, as the safest substance that erases estrogen out of your body. It has no anabolic effect, but its admission during cycle gives some benefits to athletes’ health. Athletes using steroids also have some benefits as a post cycle recovery, because 20mg dose may boost testosterone level up to 150%.
Tamoxifen citrate was discovered by AstraZeneca (former Imperial Chemical Industries) and is sold under several brand names (Nolvadex, Istubal, Valodex, Nolva). Due to expiration of the patent, it is widely sold under its generic name.
Tamoxifen use in breast cancer has wide range:
- the treatment early and advanced estrogen receptor positive breast cancer in pre- and post-menopausal women;
- hormone treatment for male breast cancer;
- prevention of developing, spreading and lowering of breast cancer risk;
- reduction of contralateral cancer.
Some breast cancer cells require estrogen to grow. Estrogen binds to and activates the estrogen receptor in these cells. Tamoxifen is metabolized into compounds that also bind to the estrogen receptor but do not activate it. Because of this competitive antagonism, the drug acts like a key broken off in the lock that prevents any other key from being inserted, preventing estrogen from binding to its receptor. Hence breast cancer cell growth is blocked.