How effective is it?
Progestin only injectable contraception is highly effective when used correctly, with a typical success rate of less than 1 pregnancy per 100 women each year.
What are the side effects?
Possible side effects can include irregular menstrual bleeding, weight gain, headaches, and mood changes. In some cases, decreased bone density, but this is reversible after stopping the injections. Fertility usually returns some time after the last injection, but this can vary among individuals.