Depo-Provera is a shot (injection) for women that prevents pregnancy. Depo-Provera is a synthetic form of the female hormone progesterone. (Progesterone is also one of the hormones used in birth control pills.) It prevents your ovaries from releasing an egg for the next 3 months. If the ovaries do not release an egg, you can't become pregnant. (Pregnancy rates for women using Depo-Provera are less than 1%.)
Every 3 months your health care provider will give you an injection of Depo-Provera. The shot is usually given in a muscle of the upper arm or buttock.
The benefits of Depo-Provera are:
It is one of the most reliable forms of birth control.
Protection against pregnancy starts 24 hours after the injection.
There are no pills to take or devices to insert, and there is no interruption of sex.
It can be used by women who are breast-feeding.
Because eventually you will stop having menstrual periods while you are taking Depo-Provera, you are less likely to become anemic.
Depo-Provera does not contain estrogen. It can be used by women who cannot take birth control pills because of the risk of cardiovascular problems from the estrogen in the pills.
At first, the increased level of progesterone in your body may cause irregular menstrual bleeding or spotting. Gradually, as your shots continue, you will stop having your periods. After you stop getting the shots, your menstrual periods will begin to return to normal.
If you decide to have a baby, it may take you at least a year to conceive after the last shot. Consider using Depo-Provera for birth control only if you know you don't want to get pregnant for at least a year.
Many women have no problems while using Depo-Provera. However, the following side effects have been reported by some women and you should watch for them:
abdominal or back pain
weakness or fatigue
decreased sex drive
Depo-Provera does not protect you against sexually transmitted diseases, such as AIDS. Latex condoms are the only safe way to protect against AIDS.
Depo-Provera should not be used if you think you may be pregnant. If you discover that you were pregnant at the time of an injection, tell your health care provider as soon as possible. The baby may have a higher risk of low birth weight.
Depo-Provera should not be used if you have breast cancer, liver disease, unexplained vaginal bleeding, or a tendency to develop blood clots.
If you have diabetes and are taking Depo-Provera, your health care provider will watch you closely for signs of increased blood sugar.
If you have a history of mental depression and are taking Depo-Provera, your provider will watch you closely for signs of depression. Stop getting the shots if your depression recurs and get help from a counselor.
Long-term use of Depo-Provera may contribute to osteoporosis (weakening of the bones). Researchers are doing studies of this possibility.