How does it work?

The contraceptive injection contains progestogen hormone which is similar to the hormone naturally produced.

It works by stopping the ovaries from releasing an egg each month (ovulation).  It also thickens the mucus in the cervix preventing sperm reaching the egg and thins the lining of the uterus so it is less likely to accept a fertilised egg.

What are the advantages?

  • The injection is over 99% effective
  • It lasts 13 weeks
  • It can be used if you are breastfeeding
  • Your period may become lighter and less painful

Are there any disadvantages?

  • Some may experience side effects including headaches, mood changes, spotty skin, weight gain and irregular bleeding
  • The injection cannot be removed from your body, so any side effects may last for the duration (8-13 weeks)
  • It can take some time for your fertility to return after stopping the injection
  • The implant does not protect you against sexually transmitted infections so you may need to use condoms too

Where can I get it?

The injection is administered by a doctor or nurse and can be done at either your GP practice or local sexual health clinic