Depo-Provera contains the active ingredient medroxyprogesterone acetate, which is a form of progesterone. It is an effective birth control method requiring intramuscular or subcutaneous injections every 12 weeks. The most common side effect is a change in the menstrual cycle. Several other important side effects are also possible.
Types of Side Effects
Depo-Provera is likely to affect the menstrual cycle. Irregular periods, spotting and heavy or continuous bleeding are all possible. This drug also lowers estrogen levels and this in turn may alter bone metabolism and lead to weaker bones. There appears to be a slight increased risk of breast cancer in women who have used Depo-Provera. Many users of Depo-Provera will gain weight, and some of this is attributable to fluid retention. Depression, anxiety and general moodiness are potential side effects associated with Depo-Provera. While rare, blood clots in the legs, lungs, brain, eyes or elsewhere may develop in those using hormonal contraceptives, according to Drugs.com.
Time Frame
The Food and Drug Administration label for Depo-Provera recommends using this drug for less than two years and monitoring bone density if it is used for longer periods, due to the risk of osteoporosis and fractures.
The FDA label notes that women under 35 whose first use of the drug was in the previous four years have a more than twofold increased risk of breast cancer, compared to those who have never received the medicine. However, the overall risk in any woman who has ever taken Depo-Provera is less, suggesting that the danger decreases over time.
The FDA label notes that the average increase in weight in the first year is about 5 pounds, with about 16 pounds gained by year six.
Reversibility
The changes in the menstrual cycle tend to dissipate over time. In fact, Drugs.com notes that after one year of injections, about half of women have no periods at all. Discontinuation of this birth control method usually leads to return of the normal menstrual cycle within 10 months, states the McKinley Health Center at the University of Illinois.
The effect on bone strength is considered partially reversible upon stopping use of the contraceptive.
Benefits
Aside from preventing unwanted pregnancies, Depo-Provera may help stabilize the lining of the uterus. Women who use this medicine have a reduced risk of endometrial cancer, according to the FDA label.
Warnings
Depo-Provera should not be administered to women who are pregnant, due to risks to the fetus. Additionally, women with breast cancer are not candidates for use. A history of blood clots or liver disease precludes the use of Depo-Provera. A known allergy or hypersensitivity to the drug, or any other ingredients in the injection, is a contraindication to its use.
