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Contraceptive injection

CONTRACEPTIVE

INJECTION

PROS

    Needs to be administered less frequently than other forms of contraception.

    Injected by healthcare professional or you may receive training to inject. It is important to return to your HCP for regular injections otherwise there is a risk of pregnancy.

    Is 94% effective at preventing pregnancy with typical use.

    Can stop periods in some women.

    Prevents pregnancy for up to 8-13 weeks.

    Does not contain oestrogen but does contain progesterone.

    Once injected, you don't need to worry about contraception in the moment.

    It can be used when breastfeeding, no sooner than 6 weeks after birth.

    Administered by a HCP. The sub-cutaneous injection should be initiated by a healthcare professional but after proper injection treatment can be self-administered.

CONS

    Your periods may become irregular, lighter, heavier or longer.

    It may take up to one year for your period and fertility to return to usual levels after discontinuation of use.

    Some women prefer hormone free options.

    Does not protect against HIV infection (AIDS) and other sexually transmitted infections (STIs).

    It may cause weight gain.

    It may cause breast tenderness.

    Can cause or worsen acne in some women.

    Some women experience mood changes, including mood swings, depression, or depressed mood.

The pros and cons listed are not exhaustive. Talk to your doctor or nurse for more information.

 

SIDE EFFECTS

All medicines can cause side effects, although not everybody gets them. Its important for you to ask your doctor for full comprehensive information for each option including understanding all potential risks, which will require an individualised medical review. The following section includes some initial considerations.

Injection side effects

You may experience side effects like headaches, acne, hair loss, decreased sex drive, weight gain and mood swings.

    The contraceptive injection may cause irregular bleeding. In some cases, it may cause shorter, lighter periods, or no periods at all.

    The contraception injection may cause weight gain in some women.

    For some women, hormonal contraception can negatively impact their mood. Some women experience mood swings when using the contraceptive injection.

    There are two different types of injectable contraceptives – one is injected by your doctor or nurse, the other can be self-injected at home.

    • Thinning of the bones
       - Using the contraceptive injection affects your natural oestrogen levels, which can cause thinning of the bones (Osteoporosis). This is not a problem for most women because the bone replaces itself when you stop the injection, and it does not appear to cause any long-term problems. Sometimes the doctor may recommend that you stop after 2 years so there's no long-term effect on your bones.
    • Injection site reactions
       - As with any injection, there’s a small risk of a reaction at the site of injection, which may cause irritation, swelling or a scar.
    • Infection
       - There's a small risk of infection at the site of the injection. In very rare cases, some people may have an allergic reaction to the injection.
    • Potential risks -
      Cancer (including breast), injection site reactions (swelling), allergic reactions to injections (symptoms include sudden wheeziness, difficulty in breathing or dizziness, swelling of the eyelids, face, lips or throat, skin rash, hives), thinning of the bones, meningioma ( benign tumour of the tissue surrounding the brain and spinal cord) and depression.


     

PP-UN-WHC-GB-0297 July 2025