In October 1992, the U.S. Food & Drug Administration approved injections (shots) of Depo-Provera for birth control use in the United States.
How does DMPA work?
Given as a shot, DMPA is a chemical about the same as the body's natural hormone; progesterone. It works by preventing the ovary from producing an egg each month, and if no egg is produced, you cannot get pregnant. It also causes changes in the lining of the uterus. The lining thins causing periods to be irregular or absent. One shot lasts for 90 days (3 months). It is important that you return on time for your shot for continued protection from pregnancy.
How effective is DMPA?
The shot is 99.7% effective - as effective as having your tubes tied or cut, but the surgery is permanent and the shot is not.
What are the advantages of using DMPA?
DMPA has been found to decrease the frequency of grand mal seizures and sickle cell crises. Also, DMPA is not affected by drugs that interfere with other methods of hormonal birth control.
Does DMPA cause any side effects?
Long-term DMPA users may develop decreased bone density. Exercise regularly and vigorously. Adequate calcium intake (1300-1500 mg/day) and vitamin D intake (400-800 IU/day) is necessary to prevent bone loss. Smoking can cause a decrease in bone density, therefore, smoking cessation is encouraged. A test is available to measure bone density.
Additional side effects can include:
- Irregular menstrual bleeding
- No periods
- Weight gain
Most women who do experience side effects during the first months report they have fewer problems as time goes on.
How is DMPA given?
One injection in the hip or upper arm will prevent pregnancy for 3 months and birth control begins when you get your first shot. The first shot will be given within 5 days after your period starts, within 5 days after you deliver a baby or have an abortion. If you are breastfeeding, you must wait 6 weeks after delivery for your first shot. You may then continue the shots even though you continue to breastfeed. It is extremely important that you arrange to come back every 90 days for your next shot. You will be given a 2 week time frame to return for your shot, but other steps have to be taken if you are late returning for your shot.
Is DMPA safe?
This shot has been used for over 30 years. There are 8 to 9 million women in 90 countries who now use DMPA and many have used it for over 10 years. It does not interfere with milk production or affect the baby of a nursing mother. The World Health Organization studies show women are not at an increased risk overall of cancer of the cervix, ovary, liver or breast. DMPA appears to protect against cancer of the lining of the uterus for at least 8 years after a woman stops the shot. DMPA has limited drug interactions, may improve endometriosis, and has been shown to decrease the frequency of seizures. It may also reduce risk of infection in the female organs (PID) and reduce yeast infections. Studies have shown that bone thickness was lower in women that had used DMPA for at least 5 years. Smoking may add to this risk. However, this condition stopped when the shot was stopped.
What changes will occur in my menstrual cycle?
During the first year most women will have changes in their menstrual periods. These may include:
- Irregular bleeding
- More or less menstrual bleeding
- No periods at all
Not having periods with DMPA is normal, especially after the second or third shot. It is not harmful to you. Once you stop the shots, periods usually return from 3 to 10 months later. You will be given a pregnancy test before you receive your first shot or anytime you are late for a shot. Remember, DMPA does not protect you against sexually transmitted diseases, so it is important to use condoms each time you have sex.