Letrozole is a medication primarily used to treat certain types of breast cancer in women who have gone through menopause. It belongs to a class of drugs known as aromatase inhibitors. These drugs work by lowering the levels of estrogen in the body. Estrogen can promote the growth of some breast cancers, particularly those that are hormone-sensitive. By blocking the enzyme aromatase, which converts androgens (male hormones) into estrogen, letrozole helps to slow down or stop the growth of these cancers. Letrozole Dosage is usually taken as a tablet once a day, and many women take it for about five years after their initial breast cancer treatment, such as surgery or chemotherapy. In some cases, it may be prescribed for longer periods. Besides treating breast cancer, letrozole can also be used to help women with fertility issues, particularly those with polycystic ovary syndrome (PCOS), as it can stimulate ovulation. Doctors monitor patients for potential side effects and overall health during treatment. Letrozole is an important option for managing hormone-sensitive breast cancer and has been shown to reduce the risk of cancer recurrence in postmenopausal women.