How does it work?
The injection contains progestogen. This thickens the mucus in the cervix, stopping sperm reaching an egg. It also thins the womb lining and, in some, prevents the release of an egg.
The injection is usually given into a muscle in your bottom.
Possible side effects
Side effects can include weight gain, headaches, mood swings, breast tenderness and irregular bleeding. The injection can’t be removed from your body, so if you have side effects they’ll last as long as the injection and for some time afterwards.
Periods and fertility may take time to return after stopping the injection, so it may not be suitable if you want to have a baby in the near future.
Where do I get it?
Visit your nearest sexual health clinic or your GP surgery.