The contraceptive injection contains the hormone progesterone and is one of the methods referred to as LARC (Long Acting Reversible Contraception).

About the injection

LARC methods require a Nurse or a GP to give them to you but are good as it means you don't have to remember to take a pill. It is usually injected into a muscle such as your bottom or upper arm.

There are two types of injections:

  • Dep-Provera - which is most commonly used in the uk
  • Noristerat

How it works

The injection works in three ways:

  • Stops your ovaries releasing an egg each month
  • Thickens the mucus around the cervix making it harder for sperm to get through
  • Makes the womb lining thinner so it is less likely to accept a fertilised egg

The injection lasts between 8-12 weeks depending on the type you have. If you have the injection during the first 5 days of your period then you will be protected against pregnancy immediately. If at any other time of the month, then you will NOT be protected against pregnancy for the first 7 days, so an alternative method of contraception will need to be used for 7 days (e.g. Condoms).

How effective is the injection?

The injection is over 99% effective against pregnancy but it doesn't protect against STIs so always use a condom!

If follow up injections are missed, you could be at risk of becoming pregnant. Remember to get the follow up injection on time.

Long acting reversible contraception (LARCs)

There are many long acting reversible contraception methods that can be used as a form of contraception (e.g. implant, injection and the IUD/IUS). The main differences between these methods and other methods of contraception are that they are long-lasting, easily reversed and you don't have to remember to take it every day.

All LARC methods are suitable for women of all ages. Other types of LARCs include: