NOLVADEX, brand of tamoxifen tablets. Tamoxifen is a medication that is used to prevent breast cancer in women and treat breast cancer in women and men.It is also being studied for other types of cancer. It has been used for Albright syndrome. Tamoxifen is typically taken daily by mouth for five years for breast cancer. It is a selective estrogen-receptor modulator (SERM) and works by decreasing the growth of breast cancer cells.