Exemestane is a medication primarily used in the treatment of hormone-receptor-positive breast cancer in postmenopausal women. It belongs to a class of drugs known as aromatase inhibitors, which work by reducing the levels of estrogen in the body. Lower estrogen levels can help slow or stop the growth of certain types of breast tumors that require estrogen to grow. This medication is typically prescribed after other treatments, such as tamoxifen, have been completed. Exemestane is taken orally, usually once a day, and may be part of a broader treatment plan that includes surgery or radiation therapy.