Injections

The contraceptive injection steadily releases the hormone progestogen into the bloodstream. If used correctly, the injection is more than 99% effective at preventing pregnancy.

What is it?

The contraceptive injection steadily releases the hormone progestogen into the bloodstream. This stops an egg from being released every month, thickens the mucus from the entrance to the womb (so it is harder for sperm to pass through to the womb and reach an egg) and makes the lining of the womb thinner (so the fertilised egg does not implant in the womb). If used correctly, the injection is more than 99% effective at preventing pregnancy.

Who can use it?

The contraceptive injection can be used without problems in most cases. However, it may not be suitable if you:

  • Think you might be pregnant.
  • Want to keep having regular periods.
  • Have been bleeding in between periods or after sex.
  • Have arterial disease or a history of heart disease or stroke.
  • Have a blood clot in a blood vessel (thrombosis).
  • Have breast cancer or have had in the past.
  • Have diabetes with complications.
  • Have cirrhosis or liver tumours.
  • Are at risk of osteoporosis.
What are the advantages?
  • Each injection lasts for 12 or 13 weeks.
  • The injection does not interrupt sex.
  • The injection is an option if you cannot use oestrogen based contraception (for example, the combined pill, contraceptive patch or vaginal ring).
  • The injection is safe to use while you are breastfeeding.
  • The injection is not affected by other medicines.
  • The injection may reduce heavy, painful periods.
  • There is an injection (Sayana Press) that you can take away and give yourself once we have shown you how in the clinic.
  • The injection offers some protection from cancer of the womb and ovary.
What are the disadvantages?
  • Disrupted periods - in the first year of the injection your periods may become irregular, but tend to become shorter, lighter and may resolve with time.
  • There can be a delay in return to natural fertility after you stopping using the injection.
  • You may experience side effects such as weight gain, acne, tender breasts, and changes in mood but these may resolve in time.
  • Thinning of the bones is a risk for those who already have increased risk of developing osteoporosis.
  • There is a small risk of infection or scarring at the site of injection. In very rare cases, some people might have an allergic reaction to the injection.
Where can you get it?

You can get the contraceptive injection for free through the NHS from our clinics or most GP surgeries.

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