How effective is “the shot?
” Depo-Provera is over 99% effective when given every 12 weeks. How does Depo-Provera work? Depo-Provera prevents ovulation (the release of an egg from a woman’s ovaries). Without an egg to be fertilized, pregnancy cannot occur. How and when is Depo-Provera given? Depo-Provera is given by injection once every 12 weeks. The first injection is often given within five days of the onset of a normal period. A back-up birth control method must be used for one week after the first injection or a late injection. What are the advantages of Depo-Provera? Depo-Provera provides excellent protection from pregnancy (almost 100% effective). Depo-Provera is also more convenient than some birth control methods because you don’t have to remember to take a pill daily, and you don’t have to interrupt your sexual activity to put in a barrier contraceptive. Since women often stop menstruating while using Depo-Provera, it improves or stops PMS and heavy menstrual bleeding. “The shot” also reduces the risk of
