Tamoxifen is the most commonly used hormone therapy for the treatment of breast cancer.
Many women have breast cancer that tests positive for estrogen receptors (ER+). This means that estrogen promotes the growth of the breast cancer cells. Tamoxifen blocks the effects of estrogen on these cells. It is often called an "anti-estrogen."
Tamoxifen slows or stops the growth of cancer cells that are already present in the body. It helps keep the original breast cancer from coming back and helps prevent new cancer in the opposite breast. It also reduces the risk of breast cancer in women who have a high risk for this disease.
In rare cases, tamoxifen is used to treat breast pain (mastalgia), because it reduces estrogen levels that cause breast swelling. This is an unlabeled use.
The drug is technically an estrogen agonist/antagonist, which competitively binds to estrogen receptors in various target tissues. With the tamoxifen molecule bound to this receptor, estrogen is blocked from exerting any action, and an antiestrogenic effect is achieved. Since many forms of breast cancer are responsive to estrogen, the ability of tamoxifen citrate to block its action in such cells has proven to be a very effective treatment.
It is also utilized successfully as a preventative measure, taken by people with an extremely high familial tendency for breast cancer.
Males : an enzyme in the male body (aromatase) is capable of altering testosterone to form estradiol. The structure of estrogen is actually quite similar to testosterone, so its presence in the male body is not all that remarkable. Since this same enzyme can also aromatize endogenous testosterone , the buildup of estrogens can be an important concern .
Males : To counter estrogenic side-effects caused by certain androgenic-anabolic Steroids
Hot flashes, nausea, leg cramps, muscle aches, hair thinning, headache, and numb/tingling skin may occur.