Fuvestrol Injection is an estrogen blocker. It is used in the treatment of breast cancer in women who have gone through menopause. It works by adjusting the level of estrogen and slow down the growth of cancer cells. Fuvestrol Injection is given as an injection into the muscles under the supervision of a doctor. It should be taken as doctor your doctor's advice. The dose and how often you take it depends 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 for you. The most common side effects of this medicine include injection site reaction, headache, vomiting, allergic reaction, and Nausea. If these bother you, or appear serious, let your doctor know. There may be ways of reducing or preventing them.