Depo Provera, also known as "the birth control shot" or just "Depo," is a synthetic hormone that is injected into the hip muscle every 12 weeks. Depo Provera prevents ovulation. It also alters the lining of the uterus making it much less likely for pregnancy to occur.
When used correctly, Depo Provera is 99.7% effective in preventing pregnancy over 12 weeks.
Depo Provera has been used safely by millions of women around the world. While Depo Provera is considered safe for most women, it is not recommended for women who have any of the following conditions:
There are serious concerns about the use of Depo and the loss of bone density. Depo use should be carefully considered by adolescents and/or those who have not achieved their peak bone mass. See the section below on health risks for more information.
Depo Provera use offers contraceptive convenience and privacy. There are no pills to remember to take every day nor are there any contraceptive devices to store. Since Depo Provera contains no estrogen, some women who cannot take birth control pills or use other methods that contain estrogen may be able to use Depo Provera. In addition, Depo Provera use seems to provide some protection from certain types of cancers.
Although Depo Provera is a long lasting contraceptive, the majority of women who wish to conceive do so within 12 to 18 months of their last injection.
The first injection must be given within 5 days of the beginning of a normal menstrual period, or within 5 days of an abortion or miscarriage or childbirth.
As long as you return every 12 weeks for another injection, you will have continuous birth control protection.
You can get your next injection up to two weeks early. However, if you are late for an injection, you should abstain or use another method of birth control until you can receive your next shot. A pregnancy test may be required if you are late for your shot.
If you breastfeed after childbirth, we recommend waiting six weeks for your first injection.
The majority of women who use Depo Provera report irregular periods and bleeding for the first 3-6 months. After that time, most women have no periods at all. This is not a harmful side effect and, in fact, some women consider the absence of periods as one of the benefits of using Depo Provera.
Other possible side effects include:
If severe side effects occur, it is important to contact your health care provider. Many women who experience side effects during the first few months of using Depo Provera find that they diminish over time.
Studies now confirm that there can be a loss of bone density with Depo Provera use, potentially putting women at risk of osteoporosis and bone fractures in later life. The bone loss is greater the longer Depo is used, and may not be reversible even after the medication is stopped.
The greatest concern is use by adolescents and women in their early 20s, who may not have reached their peak bone density. Your provider will take into consideration your age and medical history before prescribing Depo. We do not recommend you use Depo for longer than 2 years unless you are not able to take other methods of birth control.
Depo Provera might cause an increase in cholesterol and other blood fats. Depending on your medical history, periodic checks of blood cholesterol may be recommended.
If you are pregnant or become pregnant, there may be a very small risk of birth defects in the fetus. However, since Depo Provera is a highly effective birth control method, this is very rare.
A slightly increased risk of breast cancer may exist for women under 35 years of age who use Depo Provera. According to the Food and Drug Administration, worldwide studies have found the overall breast cancer risk for long-term use to be minimal if it exists at all.
Bedsider.org provides information about many different birth control methods.
Planned Parenthood's website offers information on the effectiveness of different kinds of birth control methods.
If you have any questions and are a UW student or established Hall Health patient, you may call one of our Consulting Nurses for further information.
Authored by: Hall Health Center Women's Health Clinic staff
Reviewed by: Hall Health Center Women's Health Clinic staff, January 2014