The Depo-Provera shot is an injectable form of birth control for women that contains medroxyprogesterone acetate, a man-made hormone that mimics the naturally occurring hormone progesterone. Health officials at the U.S. Food and Drug Administration warn that this form of birth control should not be used for more than two years due to its potential long-term side effects.
Decreased Bone-mineral Density
Prolonged use of the Depo-Provera birth control shot has been associated with a decrease in bone-mineral density in certain women. In clinical trials for this method of birth control, women using Depo-Provera for five years experienced a decrease in bone-mineral density of at least 5 percent in the spine, hip and neck, reports the FDA. Bone-mineral density loss due to Depo-Provera treatment can increase a woman's risk of developing osteoporosis later in life. Abnormally thin, weak or brittle bones resulting from decreased bone mineral density can make a woman more susceptible to broken or fractured bones. Women who experience unusual bone pain or frequent bone-related injuries while using Depo-Provera should contact a medical professional immediately for further evaluation and care.
Amenorrhea
Women using Depo-Provera can experience irregular vaginal bleeding as a long-term side effect of treatment. After two years of use, almost 70 percent of women no longer experienced a monthly menstrual cycle--a condition called amenorrhea, according to the FDA in clinical trials for Depo-Provera.
Breast Cancer
Women under the age of 35 who use Depo-Provera may have an increased risk of developing breast cancer later in life as a long-term side effect of treatment, according to the FDA. The direct relationship between Depo-Provera use and breast cancer development is unclear, and further clinical studies are necessary to examine this issue. Women who develop any breast-related changes, such as breast swelling, skin lesions or lumps within the breast tissue, should contact a doctor immediately for evaluation.
Weight Gain
A study published in the March 2009 issue of the American Journal of Obstetrics and Gynecology reports that women using Depo-Provera for 36 months gained an average of 5.1kg--more than 11 lbs.--during treatment. The study reports that women who switched from using Depo-Provera to another hormone-containing oral contraceptive gained an additional pound of body weight over six months. Women who switched from using Depo-Provera to a nonhormonal contraceptive, such as an intrauterine device or condoms, lost an average of 1 lb. over six months. Women using Depo-Provera should be aware that long-term weight gain side effects are common and may persist even after use of this birth-control method ends.
Delayed Fertility
Delayed fertility may occur as a long-term side effect of the Depo-Provera injection. After stopping treatment with Depo-Provera, the median time for a woman to conceive is 10 months, according to the FDA.
References
- U.S. Food and Drug Administration: Depo-Provera Prescribing Information
- American Journal of Obstetrics and Gynecology; Changes in Weight ... with Injectable and Oral Contraceptive Use; Drs. Berenson and Rahman; March 2009
- Family Doctor: Depo-Provera
- Rx List: Depo Provera
- Feminist Women's Health Center: Depo-Provera
