Contraceptive injection

What is the contraceptive injection?

It’s an injection of the hormone progestogen given every three months by a healthcare professional. It can be a good option for people who don’t get on well with contraception that contains oestrogen (combined pill, patch, contraceptive ring).

How does it work?

It’s an injection of the hormone progestogen. It stops your ovaries from releasing an egg (ovulation) each month. It also thickens the mucus in the cervix which can prevent sperm from fertilising an egg and thins the lining of the womb making it difficult for a fertilised egg to implant there.

Different types of contraceptive injection

There are 3 types of contraceptive injection:

  • Depo-Provera and Noristerat. These are typically injected into your buttock.
  • Sayana Press. This is injected either into the front of your thigh or your abdomen. You can be trained to do this yourself at home but not all clinics and GPs offer this contraceptive yet.

How long does the contraceptive injection last?

Depo-Provera and Sayana Press injections provide protection from pregnancy for 13 weeks. Noristerat is effective for 8 weeks.

How effective is the contraceptive injection?

Used correctly it’s over 99% effective. This means fewer than 1 in 100 people will get pregnant in a year using this method. When the injection isn't used correctly, for example - the date for the next injection is missed, around 6 in 100 people will become pregnant in a year 1.

Potential contraceptive injection side effects

Some people have side effects like spotty skin (acne), loss of interest in sex, headaches and mood swings.

Some people gain weight while using Depo-Provera or Sayana Press.

Things to consider when getting the injection

  • If you get your next injection late or miss it altogether you may not be protected from getting pregnant.
  • Your periods can become irregular, less frequent, longer or stop altogether and may not return to normal for a while after you stop using it.
  • It doesn’t prevent you from getting sexually transmitted infections so you might want to use condoms.
  • The injection can reduce heavy or painful periods.
  • The injection isn’t affected by other medicines or episodes of vomiting and diarrhoea.
  • It can affect your oestrogen levels and can be associated with thinning of the bones so it’s not suitable for people who have osteoporosis (or are at high risk of developing it).
  • If you do experience side effects, these may last as long as your last injection is effective for, and potentially longer whilst it wears off.
  • It can take up to a year for your fertility to return to normal after you stop getting the injection.

Where can I get the contraceptive injection?

You can get the injection for free at NHS sexual health clinics, contraception clinics, GP surgeries and some young people’s services.

Other contraception options

If the injection isn’t right for you there are other forms of long-acting reversible contraception available including the intrauterine device (IUD), the intrauterine system (IUS), and the implant. After starting these methods you are protected from pregnancy for several years.

If you’d prefer something a bit more flexible, that gives you the ability to manage your periods, you could choose from contraceptive pills, the contraceptive patch or the ring (NuvaRing). You can read more about these on our contraception information pages. If you live in an eligible borough you can order these for free online from SHL.UK, Register or Login to find out more.

Reviewed by our clinical team: December 2020 (next review date: April 2022)

1. Source: Contraceptive injections - Contraception - Sexwise