It is now also used to treat women with early stage breast cancer. This fact sheet provides information about tamoxifen, its use as a treatment for breast cancer, and its benefits, risks, and side effects. Tamoxifen is a type of hormonal therapy used to treat breast cancer. It slows the growth of some breast tumours by blocking the effect of estrogen on breast cancer cells. Estrogen is a hormone which helps some breast cancer cells grow.
Tamoxifen is taken as a pill.
You may know it by its brand and generic names, such as Nolvadex and Tamofen . Tamoxifen is used to treat breast cancer that has spread to other parts of the body. This is called metastatic breast cancer. Tamoxifen is also used after surgery to reduce the risk of the cancer coming back in other parts of the body. When used this way, it is called adjuvant therapy.