Presafe 500mg Injection is used to restore menstrual cycles in women whose periods have stopped. It is a natural female hormone important for regulating ovulation (release of an egg from a woman's ovary) and menstruation. It is used in the treatment of infertility to help you get pregnant. You should use Presafe 500mg Injection as your doctor has advised. It is generally given by a healthcare professional and should not be self-administered at home. Do not use more or less than you have been advised and do not use it for longer than recommended. You may be asked to continue taking this medicine for a period after it is confirmed that you are pregnant. The most common side effects include headache, vomiting, bloating, nausea, and abdominal pain. You may also feel less interested in sex and get pain or discharge in your vagina. Your doctor may be able to help you reduce or prevent side effects, consult with your doctor if they bother you or do not go away with time. Very occasionally people get a severe allergic reaction which needs urgent medical attention. Using this medicine may increase your risk of blood clots or breast cancer. It may not suit everybody, and you should tell your doctor if you have, or have had, breast cancer, unusual bleeding in the vagina, or liver disease. You may be monitored more carefully if you have liver, kidney, or heart problems or have diabetes or asthma. Let your doctor know your medical history to be safe. Check with your doctor about all other medicines which may affect, or be affected by, this medicine. You will probably have several tests both before and during treatment to check your womb. This medicine can alter your thinking or reactions and you may feel very tired so be careful if you drive or need to be alert.