Center for Young Women's Health

Depo-Provera® Hormonal Injections 



  • The Depo-Provera® shot is very effective at preventing pregnancy.
  • It's important to get your shot every 13 weeks (3 months).
  • Periods can be heavier initially, and then lighter, or absent while on Depo-Provera®.

hormone injection

Depo-Provera® is a female hormonal method of birth control. It's very effective in preventing pregnancy. Depo-Provera® contains a synthetic (man-made) form of the hormone progesterone, called depot medroxyprogesterone acetate (DMPA). The Depo-Provera® injection gives 3 months protection against pregnancy. You should get one injection every 3 months (13 weeks) to get the best protection against pregnancy. It's safe to get your injection up to 2 weeks early if your 3-month appointment date does not fit into your schedule.


Out of 100 women using Depo-Provera®
Typical use: 6 women become pregnant 6 Pregnant Women
Perfect use: 1 or fewer women become pregnant 1 Pregnant Woman


When do Depo-Provera® hormonal injections start to work?

Most girls get their first Depo-Provera® injection during the first five days of a normal menstrual period. You are then protected from pregnancy right after you get the injection. Another way to start DepoProvera® is “Quick start” – you get the first injection when you haven’t had sex for two weeks (or used a condom 100% of the time) and have a negative pregnancy test. You then need to use condoms for at least 7 days after the injection for additional protection.


How does Depo-Provera® prevent pregnancy?

The injected DMPA suppresses your pituitary gland which stops your ovaries from releasing eggs. Without these eggs, pregnancy can't happen. The injections also change the lining of your uterus and the mucus in your cervix. By changing your cervical mucus, the hormones make it more difficult for sperm to reach the egg.


How effective are Depo-Provera® injections?

If women get Depo-Provera® injections at the right time every 3 months, this method is more than 99% effective. This means that if 100 women get Depo-Provera® injections at the right time, less than 1 woman will become pregnant in a year.


Depo-Provera® injections do not protect against sexually transmitted infections. So you need to use a condom to lower the chance of getting STIs.


Are there other benefits of Depo-Provera® injections besides the prevention of pregnancy?

Yes. Depo-Provera® injections can cause a decrease in menstrual cramps, lighter menstrual periods (or no periods, which many young women think is a good thing), and lessen the chance of anemia.


Where can I get Depo-Provera® injections?

Your health care provider can give you Depo-Provera® injections. He/she will first want to do a physical exam and ask you about your medical history and your family's medical history. This way, your health care provider can find out if Depo-Provera® injections are a good type of contraception for you. The first Depo-Provera® injection is usually given during the first 5 days after a normal menstrual period begins. Each injection costs between $30-$100, but your insurance should cover the cost.


Are there side effects from Depo-Provera® injections?

There are possible side effects from Depo-Provera® injections. They can be different for each woman. They include:

If you get any of these side effects, talk with your health care provider. It's important for you to know that most women will have very irregular periods, especially during the first 6 months.


Should I be worried about my bones while I am on Depo-Provera®?

Researchers have found that teens are more likely to lose bone density while taking Depo-Provera®, however, bone density fortunately improves in most women after they stop Depo-Provera®. Girls also lose bone mass during pregnancy so each young woman needs to think about the risks of pregnancy compared to the benefit of effective birth control with Depo-Provera®. Your teen years, especially the years you are going through puberty (11 to 15 years), are particularly important for you to gain bone density. So until we know more, the best advice is to use Depo-Provera® at least two years after you start your menstrual periods, take in 1300 mg of calcium in your diet, take a multivitamin or 400 to 800 units of vitamin D each day, get lots of weight-bearing exercise, and maintain a healthy weight (don't be too thin). Talk to your health care provider about all options for birth control, especially after you have been on Depo-Provera® for 2 years or you have a strong family history of low bone mass (osteoporosis). Patients at risk for osteoporosis should consider using an alternative form of contraception. If you're 18 years old or older, there's much less concern about Depo-Provera®, but you should still take in calcium and vitamin D and get plenty of exercise. No matter how old you are, make sure not to smoke while on hormones.


Should I be worried if I stop getting my menstrual period while I am on Depo-Provera®?

No. Many women stop having their menstrual periods after about 6-12 months of getting Depo-Provera® injections. This is no reason to worry. It's not a medical problem and it does not mean you are pregnant. It just means that your ovaries are resting, and the lining in your uterus does not grow. So there is no menstrual bleeding. You will get your menstrual period back within 6-18 months after you stop taking the Depo-Provera® injections.


Can any woman get Depo-Provera® injections?

No. Depo-Provera® injections cannot be used by women who:

The good news is that women who can't use estrogen can still use Depo-Provera®. Depo-Provera® may also benefit patients with sickle cell disease by decreasing sickle cell attacks. Depo-Provera® may also lessen the number of seizures.


What if I want to get pregnant? Should I use Depo-Provera®?

If you want to get pregnant in the next year, you should not use Depo-Provera®, since it can prevent pregnancy for 6-10 months after the last injection. However, if timing is not an issue and you don't want to get pregnant for a couple of years, then you can use Depo-Provera® (if it's right for you) until up to one year before you want to get pregnant.


If I decide to stop getting Depo-Provera® injections, how long before I need to start using another type of contraception?

If you want to stop getting Depo-Provera® injections, all you need to do is just stop. Even though, the progesterone in the Depo-Provera® injection actually protects against pregnancy for more than 3 months, it's very important to play it safe and start using another type of contraception 3 months after your last injection.


Written and reviewed by the CYWH Staff at Boston Children's Hospital


Updated: 4/28/2014


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