About the Birth Control Shot - Depo-Provera
The birth control shot-Depo-Provera is a form of hormonal birth control. Depo-Provera is the brand name. A birth control shot lasts for 12 weeks. A pregnancy test is done before the first shot, and again any time the woman is more than two weeks late for a shot. The birth control shot is considered safe to use during breastfeeding.
How Birth Control Shots Work
The hormone in the birth control shot-Depo-Provera is progestin. Progestin is similar to progesterone, which is normally produced by a woman's ovaries as part of her menstrual cycle.
When a woman is pregnant, the level of progesterone in her body rises. One effect of this high level is to prevent ovulation. Ovulation is the release of an egg from a woman's ovary. If no egg is released, the woman cannot become pregnant. The birth control shot mimics the progesterone level in pregnancy.
The progestin in the birth control shot also prevents the uterus from developing a lining to receive a fertilized egg. If ovulation were to occur and an egg were to be fertilized, it would not be able to implant in the uterus and develop into a baby.
Effectiveness of Birth Control Shots
If used perfectly, the birth control shot is very effective. Only three in 1,000 women will become pregnant per year with perfect use. Perfect use includes never missing a dose and not taking any medicines which interfere with the birth control shot. With typical use, about three in 100 women will become pregnant over the course of one year.
If the shot is given during the first five days of a woman's period, it begins to work right away. Otherwise, the woman should use another method of birth control, such as condoms, for at least the first week. Birth control shots do not protect against any sexually transmitted diseases.
Who Can Use the Birth Control Shot?
Most women can use the birth control shot-Depo. However, women with the following conditions should not use birth control shots:
- Current pregnancy
- Undiagnosed vaginal bleeding
- Breast cancer or suspected breast cancer
- Problems with blood clots or thrombophlebitis (inflammation of the blood vessels)
- History of stroke or cerebrovascular disease
- Liver disease
- Allergies to ingredients in the shot
The birth control shot can cause fluid retention, which can worsen medical conditions such as asthma, epilepsy, migraines, and heart or kidney problems. Women with these conditions need careful monitoring to watch for problems when using the birth control shot. There is a chance that the shot could worsen diabetes, so diabetic women should be cautious as well.
Women with a history of severe depression also need close monitoring.
Side Effects of Birth Control Shots
The most common side effect of the birth control shot-Depo-Provera is a change in menstrual bleeding. Some women have bleeding in between periods, some have longer or heavier periods, and some have lighter periods. Many women find that their periods come less often, become very light, or even stop altogether. The longer a woman uses the shot, the more likely her periods will stop.
Many women gain weight after starting the birth control shot. Eating a healthy diet and exercising regularly can help minimize weight changes.
Some women have other kinds of side effects, including dizziness, headache, fatigue, nervousness, depression, or abdominal pain.
A small number of women have reported decreased sex drive, breast pain, hair loss, and depression.
Serious side effects are rare.
You can find a full list of possible side effects here.
Bone Loss and the Birth Control Shot
The birth control shot can cause bone thinning, which could contribute to osteoporosis. Bone thinning increases with longer use of the shot and improves when the shot is discontinued. Because of this problem, doctors do not recommend using the birth control shot for more than two years, unless the woman has no other option.
Cost of Birth Control Shots
Cost of the shot varies, but it is usually about $30 to $75. It is covered by some insurance plans.
Getting Pregnant after Using Birth Control Shots
If a woman's periods have stopped, they may not become normal again until a year after stopping the shot. On average, it takes about 10 months to become pregnant after stopping the birth control shot. Length of use does not seem to make a difference.
Additional Resources
- Information about the Birth Control Shot from the American Academy of Family Physicians
- A birth control guide from the Mayo Clinic
- A tool to help you choose a birth control method from the Association of Reproductive Health Professionals
- How Hormones Work to Prevent Pregnancy from the Association of Reproductive Health Professionals
