Oncolet 2.5mg Tablet helps treat breast cancer in post-menopausal women. It may be used alone or with other treatments, such as surgery or radiation. It can also be used in patients with advanced breast cancer to stop the tumor from spreading to other parts of the body. Oncolet 2.5mg Tablet is also helpful in the treatment of infertility. It can be taken with or without food, but take it at about the same time to get the most benefit. The dose and frequency depend on what you are taking it for. Your doctor will decide how much you need to improve your symptoms. You should take this medicine for as long as it is prescribed. This medicine's most common side effects include hot flashes, fatigue, increased sweating, and increased level of cholesterol (hypercholesterolemia). If these bother you or appear serious, let your doctor know. Your doctor may suggest ways to prevent or reduce these.