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CONTRACEPTIVE

INJECTION

Other names: hormonal method

WHAT IS THE CONTRACEPTIVE INJECTION?

The contraceptive injection is given as an injection into your bottom, thigh, upper arm or stomach and releases hormone into your bloodstream to prevent pregnancy.

It is a highly effective form of contraception and can last 8, 12 or 13 weeks depending on the type.

OVERVIEW

_EFFICACY

94%

_FREQUENCY

8, 12 OR 13 WEEKS

_{EFFECT ON FERTILITY}

UP TO ONE YEAR FROM DISCONTINUATION OF USE, FERTILITY SHOULD RETURN TO USUAL LEVELS

_{BLOOD CLOT RISK}

NOT KNOWN TO INCREASE RISK

THE INJECTION IS A TYPE OF LONG-ACTING CONTRACEPTION

The injection fits into the category of long-acting contraception. It is long acting because it can provide contraception for a long period of time - up to 8-13 weeks.

Learn more about long acting contraception

HOW DOES THE CONTRACEPTIVE INJECTION WORK?

The contraceptive injection steadily releases a progestogen hormone into your bloodstream, which:

Stops the ovaries from releasing an egg each month (ovulation).

Thickens the cervical mucus to make it harder for sperm to move through the cervix.

HOW EFFECTIVE IS AN INJECTION AT PREVENTING PREGNANCY?

The contraceptive injection is 94% effective at preventing pregnancy with typical use. This is because there is a chance that the injection can be incorrectly administered or administered late. With perfect use it is 99% effective.

_{PERFECT USE^*}

99
^%
+

Effective

Approximately 1 out of every 100 women in a year will experience an unintended pregnancy.

* Perfect use of a contraceptive method is when it is used correctly all the time.

_{TYPICAL USE^*}

94
^%
+

Effective

Approximately 6 out of every 100 women in a year will experience an unintended pregnancy.

* Typical use is what generally happens in real life. It takes into account human error e.g. having your injection administered late.

WHAT IS THE INJECTION MADE OF?

The contraceptive injection is an off-white suspension of a progestogen hormone (a synthetic version of the hormone progesterone). The contraceptive injection can be administered by a healthcare professional or alternatively self-administered, depending on the type you choose.

DOES THE CONTRACEPTIVE INJECTION CONTAIN HORMONE?
Yes. The contraceptive injection contains a progestogen hormone called medroxyprogesterone acetate or norethisterone enantate, which is released throughout the entire body.
It is similar to the hormone progesterone made naturally by your ovaries.
The implant does not contain oestrogen.
WHO CAN HAVE THE CONTRACEPTIVE INJECTION?
The contraceptive injection can be used in most women. In adolescents it may be used, but only after ther methods of contraception have been discussed and are considered unsuitable or unacceptable.
The contraceptive injection might not be suitable if you:
Think you might be pregnant.
Do not want your periods to change.
Want to have a baby in the next year.
Have unexplained bleeding in between periods or after sex.
Have breast cancer or have had it in the past.
Have arterial disease or a history of heart disease or stroke.
Have liver disease.
Have meningioma or have ever been diagnosed with a meningioma (a usually benign tumour of the tissue layer surrounding the brain and spinal cord).
Are at risk of osteoporosis.

PREPARING FOR YOUR GP APPOINTMENT

TALKING TO YOUR DOCTOR

Get the information you need for an informed discussion with your doctor.

LEARN MORE

PP-UN-WHC-GB-0297 July 2025