This deprives the cells of oestrogen and speeds up their natural death. Tamoxifen is absorbed into the bloodstream and carried to all parts of the body. In this way, it also reaches cancer cells that may have broken away from the main cancer and slows or stops them from growing. Tamoxifen is usually started about 1-4 weeks after surgery. If you have chemotherapy after surgery, Tamoxifen is started after chemotherapy is complete.
Tamoxifen is taken as a tablet every day.
Most women take it for 2 to 5 years. Research is currently being conducted to see if there is any benefit in taking it for more than 5 years. Tamoxifen does not cause menopause, although its side effects are similar to the symptoms of menopause. Different women may have different side effects. Some women will have few or no side effects.