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Shot Fact Sheet

What is the birth control shot?

A birth control shot is a shot or injection of the hormone progestin that prevents pregnancy by keeping the ovaries from releasing eggs. Hormones are chemicals that control how different parts of your body work. The shot also works by causing the cervical mucus to thicken, which blocks sperm from meeting with and fertilizing an egg.

How do I get it?

You can get the birth control shot at a clinic or your health care provider's office. To search for a family planning clinic near you, use the Clinic Locator.

Discuss your medical history with your health care provider before taking the birth control shot and let them know if you develop any side effects.

How do I use it?

Each birth control shot will last for 12 weeks (about three months). It is important to get each shot on time, otherwise you may get pregnant.

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Quick Facts

Effectiveness in Preventing Pregnancy

  • Of 100 women who use this method each year, about 1 would get pregnant
  • The risk is smallest in women who use the shot correctly (getting it on time)


  • Each shot is effective against pregnancy for about 12 weeks

STI Protection

  • No

Clinic Visit Required

  • Yes, only a health care provider can give a woman the birth control shot

How effective is it?

Of 100 women who use this method correctly each year (getting the shots on time every 12 weeks), about one woman is likely to get pregnant.

The shot may also not work as well for women who take certain medicines or the supplement St. John's Wort. Talk with your health care provider if you have any questions about the birth control shot.

Advantages of the birth control sho

  • The shot does not require the consent of the female's partner
  • The shot is safe and works well in preventing pregnancy. Using the shot means you do not have to think about birth control when you want to have sex
  • Many women who use the birth control shot have lighter periods (or no periods at all) and fewer cramps
  • Women who take the shot are less likely to have cancer of the uterus and pelvic inflammatory disease (PID)

Drawbacks of the birth control shot

  • Does not protect against sexually transmitted infections (STIs)
  • Requires a clinic visit every 12 weeks
  • It may take up to a year after stopping the shot to become pregnant
  • Some women experience side effects such as breast tenderness, spotting or bleeding between periods, weight gain, and headaches
  • Using the shot longer than two years may cause thinning of a woman's bones, and this can worsen the longer she uses the shot. However, normal bone growth returns when a woman stops taking the birth control shot


Office on Women's Health:

Centers for Disease Control and Prevention

Food and Drug Administration