How it works:

The birth control shot contains the hormone progestin and is given every three months by a doctor or nurse. Progestin works by stopping ovulation, which means there is no egg for sperm to fertilize. It also makes it more difficult for sperm to swim and meet an egg. When you get the shot on time every three months, it is greater than 99% effective at preventing pregnancy. However, in real life about 6 in 100 women will get pregnant if they don’t get it on time, every three months. This reduces its effectiveness to 94%.


  • Easy to keep private

  • Can make periods lighter

  • Don’t have to take a daily dose

  • Can stop using it on your own


  • Must remember to get a new shot every 12-13 weeks

  • Administered by healthcare professional only

  • Doesn’t protect against sexually transmitted infections (STIs)