Depo provera is an injectable contraceptive method that is given every 13 weeks (approximately every 3 months). The patient must remember to come to the doctor's office every 3 months for the injection, but it is otherwise effortless. It is a standard intramuscular injection that is given by the office nurse. It is 99.5% effective with perfect use, and 97% effective with typical use. It prevents ovulation and is useful in patients with endometriosis and it decreases menstrual blood loss. Eventually (especially after one year of use) depo provera users may not get menses at all.
Depo provera can cause irregular vaginal bleeding (especially in the first year of use), mood changes, delayed return to fertility (it may take nine months for ovulation to resume after the last dose of depo provera, so if the patient is contemplating a pregnancy in the near future, this may not be the best choice). Weight gain for the first year of use is approximately 5 lbs, and this can be very distressing for some patients. Depo provera can be used safely during breastfeeding and is particularly good for patients with seizure disorders, and patients who can't use estrogen, such as smokers over the age of 35.