Do not share this medication with anyone else. Notify your doctor immediately if you develop unusual weakness or drowsiness, confusion, pain or swelling in your legs, shortness of breath, blurred vision, bone pain, menstrual changes, abnormal vaginal bleeding, or pelvic pain or pressure. Tamoxifen blocks the actions of estrogen in a woman's body. Certain types of breast cancer require estrogen to grow.
Tamoxifen is used to treat and prevent some types of breast cancer that require estrogen to grow.
Tamoxifen may also be used for purposes other than those listed in this medication guide. Before taking tamoxifen, tell your doctor if you have any other medical conditions or if you take any other medicines. You may require special monitoring during treatment. This means that tamoxifen is known to harm an unborn baby. Do not take tamoxifen without first talking to your doctor if you are pregnant.