Aromatase inhibitors are a class of medications that block the enzyme aromatase, which is responsible for converting androgens into estrogens in the body. By reducing estrogen levels, these drugs are often used in the treatment of certain types of breast cancer, particularly in postmenopausal women, where estrogen can promote tumor growth. Common examples of aromatase inhibitors include anastrozole, letrozole, and exemestane. These medications can help lower the risk of cancer recurrence and are typically prescribed after surgery or radiation therapy. Side effects may include hot flashes, joint pain, and fatigue, but they are generally well-tolerated.