FASLODEX, also known by its generic name fulvestrant, is a prescription medication used in the treatment of certain types of breast cancer, specifically hormone receptor-positive metastatic breast cancer in postmenopausal women. It belongs to a class of drugs known as estrogen receptor antagonists. FASLODEX works by binding to the estrogen receptors on the cancer cells, blocking the effects of estrogen on these cells, which can slow or stop the growth of the tumor. It is typically administered through an injection into the muscle, usually once a month. FASLODEX is often considered for use in patients who have not responded well to other forms of hormone therapy. Its use and dosage may depend on the specifics of the patient's condition and how well they tolerate the treatment.