The contraceptive injection contains the hormone progestogen and offers medium term prevention of pregnancy.

It is 99% effective at preventing pregnancy.

How it works

How to use it

There are three types of injection available in the UK:

  • Depo Provera is the most common and lasts for 12 weeks
  • Sayana Press lasts for 13 weeks
  • Noristerat lasts for 8 weeks.

A doctor, nurse or clinician will inject you, either in the muscle of your bottom or upper arm (Depo Provera/Noristerat), or into the skin of the thigh or abdomen (Sayana Press).

Once you’ve had the injection, you don't have to think about contraception for the specified period, though you should make a note of when it will wear off.

What it does

The injection prevents pregnancy by:

  • Preventing the ovaries from releasing an egg each month (ovulation).
  • Thickening the mucus in the neck of the womb, so it is harder for sperm to penetrate the womb and reach an egg.
  • Thinning the lining of the womb, so there is less chance of a fertilised egg implanting into the womb.

Pros and Cons


  • The injection doesn’t interrupt sex.
  • It works for 8, 12 or 13 weeks (depending upon which one is used).
  • It may reduce heavy periods and period pain. By the end of the first year, 70% of people's periods stop.
  • 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 STIs.
  • It can cause acne.
  • There can be a very small risk of infection at the site of the injection.


The Sayana Press injection is designed to be self-administered, as well as usable in a clinic. It is a single use subcutaneous injection. This means the needle must be inserted into the fatty layer beneath the skin.

It is designed for you to do the injection yourself. It is pre-filled and ready to use in the comfort of your own home. The needle is much smaller and shorter than the injectable that you have in a clinic (Depo-Provera).

If you want to use a self-injectable, you first need to make an appointment in a clinic, and have a consultation with one of our clinicians. They will be able to make sure the self-injectable is appropriate for you and show you how to safely and effectively do the injection yourself.

If you have previously been show how to use a self-injectable in clinic, you can order a repeat delivery of the injection.


How quickly will the injection start to work?

If you have the injection during the first five days of your period, you will be immediately protected against becoming pregnant.

If you have the injection on any other day of your cycle, you will not be protected against pregnancy for up to 7 days. Use condoms or another method of contraception during this time.

What happens if I get the injection late?

If you think your next injection is late, use condoms until you know that your injection is definitely protecting you again.

If you have had unprotected sex and are worried you may need to use emergency contraception.

What if I have the injection and then do not find it suitable?

Once it is inserted you cannot remove the injection but its effects will wear off after 8-13 weeks, depending on the type used.

Will the contraceptive injection affect my future fertility?

It can take up to one year for your fertility and periods to return to normal after the injection wears off, so it may not be suitable if you want to have a baby in the near future.

Irregular bleeding may also continue for some months after you stop the injections.

Does getting the contraceptive injection hurt?

It is similar to getting any other injection such as pre-travel vaccinations.

I am approaching menopause, can I have the injection?

If you are over 50 you should consider alternative methods of contraception. Those approaching the menopause should discuss their risk of osteoporosis with their health care provider.

Will there be any long term effects on my health?

Some research has shown Depo Provera is associated with a small loss in bone mineral density, which then returns to normal within a few years of stopping the injection.

Can I have the Injection after having a baby/while breastfeeding?

Yes, the injectable contraception can be used after having a baby and while breastfeeding.

I’ve had a serious health condition. Can I use the contraceptive injection?

The injection may not be suitable if you have or have had any of the following:

  • Liver disease
  • Risk factors for osteoporosis
  • Breast cancer
  • Systemic lupus erythematosus
  • If you are under 18 or over 50 years

Speak to your GP about whether it is suitable for you.