The Shot, or Depo- Provera®, contains a large dose of a progestin hormone that stays in the body for 3 months.
How does it work to prevent pregnancy?
Progestin stops the ovary from releasing an egg, so there is no egg for the sperm to fertilize. The shot also causes thickening of the mucus of the cervix, and thinning of the lining of the uterus that can help prevent pregnancy.
How effective is it in preventing pregnancy?
The shot is highly effective. Typically, only 3 of 100 couples become pregnant in the first year.
How effective is it in preventing STDs?
The shot is NOT AT ALL effective in preventing STDs or HIV. If a person has sex, condoms must ALSO be used to reduce the risk of STDs and HIV.
Other Things to Know about the SHOT:
Advantages:
- A couple does not have to remember to do something during sex to prevent pregnancy
Disadvantages:
- Women on the shot do not have regular monthly periods
- Some women have irregular bleeding, and some have no bleeding at all. This is normal with the shot
- The shot can cause weight gain and feeling tired
- A woman must go to a doctor or clinic to receive the shot
Acknowledgement: This fact sheet was adapted from PlannedParenthood.org, and BigDecisions.org, websites that provide education about reproductive and sexual health.
Special Thanks: Melissa A. Habel, MPH, Health Scientist, Division of STD Prevention Centers for Disease Control & Prevention
