Contraceptive injections and implants

The contraceptive injection contains the hormone progestogen. It works by thickening the mucus in your cervix and it may stop your ovaries releasing an egg. It is 97% to 99% effective in preventing pregnancy.

You will need to have an injection every 12 weeks.

Effects of the contraceptive injection

• You may get irregular or long periods, but this usually improves after 6 to 12 months. Most women have no periods at all when they have been using the injection for a while.
• You may gain a small amount of weight but many women have no change in weight, and some lose weight.
• There is a small chance of bone thinning, which improves once you stop using it.
• You may not be able to get pregnant for 6 to 12 months after stopping the contraceptive injection.

A contraceptive implant is made up of 2 small, flexible rods that are put under your skin, usually in the inner side of your upper arm. The rods release small amounts of the hormone progestogen.

The implant works by thickening the mucus in your cervix. It may stop your ovaries releasing an egg.

The implant is 99% effective at preventing pregnancy and can last up to 5 years.

A trained healthcare provider puts in the implant using a local anaesthetic. You can have it removed at any time.

Your periods may become irregular or longer than usual, particularly in the first 6 months.

See your healthcare provider, Sexual Wellbeing Aotearoa Clinic or school clinic to find out if longer-lasting contraception is right for you.

Sexual health visits with your general practice team may be free. Ask them to check if you are eligible.

Appointments at Sexual Wellbeing Aotearoa clinics are free for New Zealand residents if you are under 22.

Sexual Wellbeing Aotearoaexternal link

Sexual health clinics can also offer contraception advice and emergency contraception.

Sexual health clinics

Find your local sexual health clinic — Just the Factsexternal link

Emergency contraception