It can increase survival for some women with breast cancer and significantly reduce their risk of developing cancer in the opposite breast. Tamoxifen is sometimes used for patients whose breast cancer recurs. It is also being tested to see if it can prevent the development of breast cancer in unaffected women who are at an increased risk because of a strong family history of the disease.
Tamoxifen is taken by mouth.
Tablets are either 10 mg or 20 mg. The usual dose is 20 mg daily. It is usually started after surgery or after the completion of radiation treatment. If you have chemotherapy after surgery, your treatment with Tamoxifen will start after you have finished the chemotherapy. You can take Tamoxifen with or without food, at any time during the day, but you should take it at the same time each day.