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Birth Control Shot


Effectiveness in Preventing Pregnancy

  • Of 100 women who use this method each year, about six may become pregnant.
  • The risk of pregnancy is lower in women who get the shot on time.
  • Injections every 12 weeks.
  • No STD protection.
  • Office visit required.

What is the birth control shot?

The birth control shot is an injection of progestin, one of the hormones found in birth control pills. Hormones are chemicals that control how different parts of your body work. The shot prevents pregnancy by keeping the ovaries from releasing eggs. It also causes cervical mucus to thicken and the lining of the uterus to thin. This keeps sperm from reaching and fertilizing an egg.

The most commonly used injectable contraceptive is depot medroxyprogesterone acetate (Depo Provera).

How do I use it?

Your healthcare provider needs to give you the birth control shot. Each shot lasts for about 12 weeks (about three months). It is important to get your shot on time, otherwise you may become pregnant.

How effective is it?

Of 100 women who use this method each year, six may become pregnant. This includes women who do not get the shot on time.

How do I get it?

Discuss your medical history with your healthcare provider before using the birth control shot.


Advantages of the birth control shot

  • The birth control shot is safe and works well to prevent pregnancy.
  • The shot is required about four times a year. Compared to birth control pills, it may be easier for some women to manage the birth control shot since daily pills can be missed more easily.
  • 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 menstrual cramps.
  • It is private. It is your choice if your partner knows about it.

Drawbacks of the birth control shot

  • The birth control shot does not protect against sexually transmitted diseases (STDs), including HIV, and may increase the risk of getting an STD if your sexual partner has an STD.  Always use a condom to reduce the risk of STDs.
  • It requires a visit to a healthcare provider every 12 weeks.
  • It may take longer after stopping the shot to become pregnant, especially the longer you use the shot.
  • Using the shot continuously for more than two years may cause some thinning of a woman’s bones. However, normal bone growth returns when a woman stops taking the birth control shot.
  • Side effects of the birth control shot experienced by some women include breast tenderness, spotting or bleeding between periods, weight gain, nervousness, abdominal discomfort, and headaches. Let your healthcare provider know if you have any of these side effects.

Did You Know?

Condoms add extra protection against pregnancies and STDs when used with other birth control methods.

Learn More About Condoms

Content created by Office of Population Affairs
Content last reviewed on October 11, 2017