Healthy lives for young people
  • Help & Advice
  • Find a Service
    Close icon

Contraceptive injection

The contraceptive injection contains the hormone progestogen. This is similar to the hormone progesterone that is naturally produced in the ovaries and works to prevent pregnancy.

Quick guide

How it works

The injection contains the hormone progesterone and works in three ways to prevent pregnancy from occuring. Read more

Pros & cons

The injection is over 99% effective
It doesn’t interrupt sex
Periods may be irregular, heavier, and longer or they may stop all together
It doesn’t protect you against sexually transmitted infections

Read more

Where to get the injection

The injection is available free of charge from contraceptive clinics, your GP and Brook. Find your nearest using our find a service tool. Read more

How it works

Pregnancy happens when sperm reaches an egg and fertlises it. The injection works in three ways to interrupt this process:

  • It stops ovulation
  • It thickens the mucus around the cervix, which makes it harder for sperm to get through
  • It makes the lining of the womb thinner so that a fertilised egg cannot implant

The injection is a method long-acting reversible contraception (or LARC). These methods don’t rely on you remembering to take them, but they do need a trained doctor or nurse to administer or fit them for you.

The most commonly used injection is Depo-Provera (or DMPA). Depo-Provera and Noristerat must be administered by a doctor or nurse. However, there is now an injection called Sayana Press which you can be taught to inject yourself at home.

Pros & cons


  • The injection is over 99% effective
  • It doesn’t interrupt sex
  • The injection works for 8, 12 or 13 weeks (depending upon which one is used)
  • It may reduce heavy periods and period pain
  • It can be used by some people who cannot use the contraception that contains oestrogen
  • The injection is not affected by vomiting, diarrhoea or antibiotics (like some methods)
  • Using Sayana Press (self-injection) may mean only one visit to the clinic per year


  • Periods may be irregular, heavier, and longer or they may stop all together
  • It can cause slight thinning of the bones by reducing bone mineral density (this usually recovers once the injections stop)
  • It may take a while for your periods to return to normal when you stop having the injection
  • Some people may put on weight when they use Depo-Provera
  • It can cause some side effects including headaches, mood swings, breast tenderness and irregular bleeding. Because the injection can’t be removed from your body (like an IUD, IUS or implant) if you do have any side effects they are likely to last as long as the injection and for some time afterwards
  • It doesn’t protect you against sexually transmitted infections (STIs), so you will need to use a barrier method such as condoms
  • It can cause acne
  • There can be a very small risk of infection at the site of the injection

Where can you get the injection?

The injection is available free of charge from contraceptive clinics, your GP and Brook. Find your nearest using our find a service tool.

What happens at an appointment?

Contraception and sexual health services such as Brook are free and confidential, including for people under the age of 16. Health professionals work to strict guidelines and won’t tell anyone else about your visit unless they believe you’re at serious risk of immediate harm. Find out more about Brook’s confidentiality policy.

You will need to see a doctor or nurse to discuss which of the three injections is most suitable for you. Sayana Press (the one you inject yourself) is not available everywhere at the moment.

When you go to get the injection, an appointment will typically include:

  • A few questions about your medical and family history, to work out what would suit you best.
  • The doctor or nurse will take your blood pressure and they will weigh you.

Depending on the type, you will need to go back to the clinic either 8, 12 or 13 weeks for your next injection. If you are using the Sayana Press (which you inject yourself at home) you only have to go back to the clinic annually because you will be given a years supply.


You will not be required to have an internal or breast examination for the injection.

Can you use the contraceptive injection yourself?

Sayana Press is currently the only type of injection that you can use yourself at home. The nurse or doctor will teach you how to inject yourself and also how to dispose of the needle safely. You will be given a yearly supply of the injection to use at home (every 13 weeks).

Starting the contraceptive injection

You can have the injection at any time in your menstrual cycle if you are certain you are not pregnant. If you’re given the injection during the first five days of your period you will be protected against pregnancy immediately.

If you have the injection on any other day of your cycle you will not be protected for the first seven days, so you will need to use another method of contraception, like condoms. You may also be required to take a pregnancy test after the injection has been given.

NameHow often are the injections?Site of injection
Depo-Provera12 weeks Buttocks or arm
Noristerat8 weeksButtocks
Sayana Press13 weeksFront of the thigh or abdomen


Follow-up injections must be given on time. If you think your next injection is late use condoms until you know that your contraception is definitely protecting you again.


    Other Stuff you might find useful…

    Get free condoms
    Real Stories
    Finding the right contraception for me: Iona’s story
    Real Stories
    Contraception, hormones and mental health: Georgia’s story
    Real Stories
    Endometriosis: Libby’s Story
    Myths about long-acting reversible contraception (LARC)
    Condom excuses (and comebacks!)
    Emergency Contraception: The IUD or the Morning After Pill
    12 common mistakes when using condoms
    Penises & testicles
    How do I use a condom?
    Talking about condoms with your partner


    Find a Service near you