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Levonorgestrel (intrauterine system - IUS)

lee-voe-nor-jes-trel

What does it do?

Levonorgestrel is a progestogen hormone used to prevent pregnancy, or to treat heavy periods or endometriosis. See Sexual Wellbeing Aotearoa for more information.
For information on oestrogen, see Menopausal hormone therapy (MHT) gel, patch, pessary, tablets, or vaginal cream, and the Australasian Menopause Society.

Before you start

  • It's important to make sure you're not pregnant.
  • Tell your doctor if you, or someone in your family, has ever had breast cancer.
  • Your IUS is effective at preventing pregnancy straight away if it is inserted within 7 days of the start of your period. If it is inserted after this, you need to use condoms (or don’t have sex) for the next 7 days.

How is it given?

An IUS is a small device that is put inside your uterus by a health professional. Avoid having sex or using tampons or a menstrual cup for 48 hours after your IUS is put in.
Jaydess®: your IUS can stay in place for up to 3 years.
Mirena® for preventing pregnancy: your IUS can stay in place for up to 8 years.
Mirena® for heavy periods: your IUS can stay in place for up to 5 years, or 8 years if your symptoms have not returned.
Mirena® for MHT: your IUS can stay in place for up to 5 years.

Can you take other medicines?

Tell your pharmacist or doctor about all medicines or treatments that you may be taking, including vitamins, herbal products or recreational drugs.

What side effects might you notice?

You may have period-like cramps or feel faint when your IUS is inserted. Taking paracetamol or ibuprofen, and having something to eat before your appointment can help prevent this. You may also want to have someone to drive you home, and be able to rest for a while afterwards.

Side EffectsRecommended action

Severe tummy pain, heavy bleeding, or pain after sex

Tell your doctor immediately

Changes in periods

Irregular bleeding is common in the first 3-6 months. This is not harmful and usually improves with time. After this, some women will not have any periods at all.

Mood changes

Headache

Acne

Weight gain

Sore breasts

Nausea, bloating

Vaginal itch/discharge

Tell your doctor if troublesome

If you notice any other effects, discuss them with your doctor or pharmacist.

Other information:

  • Sometimes the IUS can come out by itself. You should be able to feel the IUS threads inside your vagina. Check the threads are still in place after each period, or at the start of each month. If you can’t feel the threads, you should use a condom (or don’t have sex) until your health professional has checked the IUS is still in place. Talk to your doctor if you think you may be pregnant.
  • Your IUS does not protect you from sexually transmitted infections.
  • Having an IUS doesn't make it harder to get pregnant if you want to later on. You can get pregnant as soon as your IUS is removed.

This leaflet contains important, but not all, information about this medicine.

Prepared by the MyMedicines Committee at Christchurch Hospital, Te Whatu Ora - Waitaha, New Zealand. May 2026

For more general information about this sheet and its contents, see: What does a My Medicines sheet cover?

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About My Medicines

My Medicines Patient Information Leaflets (PILs) contain important, but not all, information about the medicines they describe.

For more information about the sheets, see: What does a My Medicines sheet cover?

My Medicines is developed by a team at Te Whatu Ora – Waitaha. Our team is made up of doctors, pharmacists, and a non-medical person to help us keep to plain language. We also discuss our information with specialist health professionals or groups when needed