In Aotearoa New Zealand Mirena® is the intrauterine device (IUD) used for the treatment of endometriosis and heavy periods or excessive menstrual bleeding (also called menorrhagia).
IUDs are often used for contraception to prevent pregnancy, but Mirena is also used as a treatment for heavy or painful periods, even in women who don't need contraception.
Note: The information on this page is about Mirena for heavy periods and endometriosis. For information about Mirena for contraception, see IUDs for contraception.
Mirena is a small, white T-shaped plastic device made of a stem attached to 2 removal threads that is placed inside your womb (uterus). It slowly releases the hormone progestogen (as levonorgestrel). This makes the lining of your womb thinner, making you less likely to have menstrual bleeding and reducing heavy, painful periods.
Once fitted, Mirena lasts for up to 5 years. It can be inserted at your GP clinic and you generally don’t need an operation or a general anaesthetic to have it fitted.
The number of spotting and bleeding days may increase when you first have a Mirena fitted but then the amount of bleeding you have during your periods slowly decreases.
It can take a few months for Mirena to reach its full effect, but by 6 months, most women will only have light bleeding and sometimes no bleeding at all. Bleeding may also be irregular.
The IUD can be fitted at any time but you should only have an IUD inserted if it’s certain you’re not pregnant or don’t have a sexually transmitted infection such as chlamydia or gonorrhoea.
The IUD is usually fitted towards the end of a period or shortly afterwards, to ensure you’re not hapū. You can also be advised to get one fitted 4 – 6 weeks after your pēpi is born or straight after an abortion.
Before the IUD is fitted, you'll need to have a vaginal examination. The doctor or nurse will pass a small instrument into your womb (uterus) to check its size and position.
The IUD is then fitted using a small plastic insertion device.
Light vaginal bleeding may also occur for a short while afterwards. Use pads rather than tampons or menstrual cups for the first few days after your IUD is fitted.
It’s also recommended to avoid sex, swimming and baths for the first few days after a Mirena is fitted.
Your healthcare provider will usually want to check that there are no problems a few weeks after fitting an IUD. This is best done after your next period. After this, there is no need for any routine check until it is time to remove the IUD. However, contact your healthcare provider at any time if you have any problems or queries.
Most women have no problems, and the IUD can remain in place for up to 5 years.
Read more about how to prepare for your appointment and what to expect after IUD insertion – Intra uterine Device (IUD)(external link) Sexual Wellbeing Aotearoa (formerly Family Planning NZ).
Checking the IUD is in place
You’ll be taught how to feel for the threads of the IUD so you can check it’s in place. It’s best to check the threads regularly, after each period or at the beginning of each calendar month.
If you can’t feel the thread, it doesn't necessarily mean that the IUD has fallen out. Sometimes the thread is just difficult to feel or has been pulled up into the cervical canal (which won’t harm you).
Contact your healthcare provider if you can’t feel the IUD thread.
Other information
Other medicines: The levonorgestrel in Mirena interacts with some medicines (eg, antiseizure medicines such as carbamazepine, lamotrigine or HIV medicines), herbal supplements (eg, St John’s Wort) and rongoā Māori, so check with your healthcare provider before starting any new medicines or supplements.
Replacement: Mirena works for a maximum of 5 years. At the end of this time, your IUD will need to be replaced with a new one.
Pregnant: If you become pregnant, contact your healthcare provider.
Removal: The IUD can be taken out at any time if you’d like it removed. This needs to be done by a trained healthcare provider.
The pain experienced during and after the fitting or removal of an IUD is different for everyone.
If you’re worried about discomfort during and after the fitting or removal of an IUD, it’s a good idea to talk to your healthcare provider beforehand to discuss your options.
You can take a support person with you during the fitting or removal of the IUD.
During the fitting of the IUD
Many women feel some discomfort or pain during the procedure. Factors such as the type of IUD (hormonal or copper), your pain tolerance, and whether you’ve given birth before can influence how painful it feels.
The pain might feel like cramping or a sharp pinch that lasts for a few minutes. Some compare it to a strong period cramp.
To help reduce pain during the procedure, your healthcare provider may suggest taking over-the-counter pain relievers such as paracetamol and ibuprofen about one hour before the procedure.
It’s important to tell your healthcare provider if you’re having pain during the procedure.
Video: IUD insertion and pain - what to expect with Dr McNamee
(Sexual Health Victoria, Australia, 2023)
After the fitting of the IUD
It's common to experience cramping after the IUD has been inserted and fitted in place. In some people the cramps may be mild and go away within a few hours. Others may have stronger period-like cramps for a few days afterwards.
The intensity of the cramps can vary, but they usually lessen over time. You can use pain relievers such as paracetamol and ibuprofen. A hot water bottle or heat pad may also help.
If you experience a sudden and severe attack of pain or any continuous lower abdominal pain, you should seek medical advice.
During removal of the IUD
The pain level when removing an IUD can also vary from person to person. Some people get mild discomfort or cramping during the procedure, while others might feel more significant pain.
The removal process typically only takes a few minutes, and while it may feel uncomfortable, it's generally quick.
In some cases, they may recommend taking pain relief before the procedure to help manage discomfort. In rare cases, if the IUD is difficult to remove or embedded, it might require additional steps, which can be more uncomfortable.
Like all medicines Mirena can cause side effects, although not everyone gets them.
Side effects
What should I do?
Pain, cramps
Light bleeding
Dizziness
Feeling weak, feeling faint
This can occur after Mirena is inserted.
If these symptoms continue for more than a few days, tell your healthcare provider.
Irregular bleeding
Heavier or lighter periods
Bleeding or spotting in between your periods
These are very common.
They usually happen in the first few months after insertion of Mirena and often settle with time.
If thee bother you or the bleeding continues, tell your healthcare provider.
Weight gain
Less interest in sex
These are common.
Tell your healthcare provider if these bother you.
Signs of infection such as severe pain in your lower tummy area, fever, flu-like symptoms, feeling unwell, dizziness, feeling faint, pain during sex or vaginal discharge
There is a small risk of infection, especially within the first 20 days after insertion.
Tell your healthcare provider immediately or phone Healthline 0800 611 116.
The IUD may come out by itself, because of muscular contractions of your womb.
This is rare but the risk increases if you normally have heavy periods or have a high BMI.
If you can't feel the threads and you could before or if you can feel the plastic stem of your IUD tell your healthcare provider straight away.
Depression or nervousness
Migraine or severe headaches
These are common.
Contact your healthcare provider or phone Healthline 0800 611 116.
In Aotearoa New Zealand Mirena® is the intrauterine device (IUD) used for the treatment of endometriosis and heavy periods or excessive menstrual bleeding (also called menorrhagia).
