Depo-Provera, also called the birth control shot, is an injectable form of contraception for women. Depo-Provera is over 99 percent effective when used properly, although effectiveness decreases when too much time goes between shots, according to Planned Parenthood. Although most of its side effects are mild, the drug does carry some risks, such as the development of osteoporosis, especially with long-term use.
Mechanism
According to Drugs.com, Depo-Provera uses medroxyprogesterone acetate, a synthetic form of progesterone, to suppress ovulation. Depo-Provera also thins the uterine lining, making implantation of a fertilized egg less likely. Another effect of the drug is an altering of the cervical mucus, which causes the mucus to become less permeable to sperm, thereby making conception less likely.
Usage
Depo-Provera is available by prescription only and may be injected into a muscle by a doctor or nurse, or self-injected after a health care professional teaches the patient the correct way to inject the drug. Injections are given every 12 weeks, beginning with an injection given within five days of the start of a menstrual period. The shot does not become effective until seven days after the first injection, so a back-up method of birth control should be used during those seven days. As long as the patient does not go more than 13 weeks between shots, protection remains continuous after the first shot takes effect.
Side Effects
Serious side effects from Depo-Provera are rare, but mild symptoms may be more common. About 50 percent of women on Depo-Provera stop having menstrual periods within the first year of use, explains the Cleveland Clinic, although most women begin having periods again after stopping their treatment. Other women may experience irregular periods or spotting between periods. Additional potential side effects include hair loss, acne, headaches, dizziness, growth of facial hair or body hair, weight gain, changes in appetite and depression.
Risks and Complications
Women who take Depo-Provera over long periods of time are at risk for developing osteoporosis, an incurable loss of bone density. Women are advised to take Depo-Provera for no longer than two years because of this, according to Drugs.com. After stopping Depo-Provera, it may take 10 months or more for regular ovulation to resume, so women who plan on becoming pregnant after stopping this drug should take this into account.
Contraindications
Women who have a history of liver disease, blood clots or breast cancer should not use Depo-Provera. If a woman has any abnormal vaginal bleeding, this may also be a reason not to use this form of birth control. Women who are pregnant should not use Depo-Provera and those who become pregnant after receiving the shot should inform a doctor immediately since this drug can cause birth defects.
