Hi, Depo provera is a hormone used mainly as birth control method. It contains medroxyprogesterone which is a man-made hormone analogue. It prevents you from conception by suppress the ovulation, prevents the changes in the lining of the uterus and making the vaginal fluid thick which prevents the motility of the sperm. Progesterone has contraceptive period for up to 12 weeks. It also reduces the bleeding and pain during cycles. Headache, nervousness, dizziness are some of the common symptoms of progesterone injection. Weight gain is also seen in some individuals. But considering the benefits on comparing with other contraceptives, progesterone is advised. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Pradeepraj, General & Family Physician