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Side effects and risks of the contraceptive injection

Side effects of the contraceptive injection

Common side effects of the contraceptive injection include:

  • changes to your periods, such as periods stopping, being irregular or lasting longer – the longer you use it the more likely it is that your periods will stop completely
  • putting on weight
  • pain, a small lump or a scar where the injection is done

Some people report acne, lower sex drive, mood changes, hot flushes and headaches. There is not enough evidence to say if the contraceptive injection causes these.

If you have side effects and they’re a problem for you, speak to a doctor or nurse.

Risks of the contraceptive injection

There are some other problems linked to taking the contraceptive injection. But the chance of getting these is small. If you have any concerns, speak to a doctor or nurse.

Bone health

Using the contraceptive injection for more than 1 year can cause your bones to become weaker.

Your bones are likely to return to normal after you stop having contraceptive injections.

Cancer

The contraceptive injection can slightly increase your risk of getting:

The risk is very small and is likely to get smaller after you stop having the injection.

Page last reviewed: 8 February 2024
Next review due: 8 February 2027