An injection that releases hormones into your bloodstream to prevent pregnancy and lasts for 8 or 13 weeks, depending on the type.
Perfect use: More than 99% effective. Fewer than 1 in 100 women will get pregnant in a year when using contraceptive injections regularly.
Typical use: Around 94% effective. Around 6 in 100 women will get pregnant in a year.
You should talk to your doctor or health professional about risk factors such as smoking, your age or medical history before you have the injection.