Depo-Provera. Nurse's hands prepare an injection of the female contraceptive Depo-Provera. Packaged vials are seen. This long-acting contraceptive is injected deep into the muscle, usually of the thigh, and is then slowly released into the blood- stream. Depo-Provera is a progesterone (medroxy- progesterone acetate) contraceptive. The usual dose is 150mg in the first five days of the menstrual cycle, or 6 weeks after birth. Contra- ception lasts for 3 months after which time the dose is repeated every 3 months. Depo-Provera is as effective as oral contraceptives. It may also be used as a hormone therapy for breast cancer and endometriosis.