The Mirena® IUD is a small plastic device that is inserted in the uterus. It contains a single hormone (progesterone type). It is released slowly. It is released directly into the uterus lining so there is less absorption in the body. It is highly effective as a contraceptive (99.9%). It works by thinning out the lining of the uterus over a few weeks/months and preventing build-up of lining. It makes it an unfavourable place for an embryo to implant. It also thickens the mucos in the cervix (entry to the womb) so prevents sperm from getting into the uterus.
Traditionally, the Mirena IUD has been licensed for 5 year use. However, as of 2024, the following changes have been made:
🔔 If the main purpose of the Mirena is for contraception (preventing pregnancy), then the Mirena can remain inside for 8 years. The contraceptive effect of Mirena® may drop slightly in Years 6-8 but is still over 99.6%.
🔔 If the main reason for using the Mirena is for managing menstrual flow and frequency, or for ‘endometrial protection (e.g. those using estrogen, or with endometrial hyperplasia), then the Mirena IUD is still for 5 year use. The hormonal dose is not high enough to protect the uterus for longer than 5 Years and needs to be replaced after that time for endometrial protection.
👉 If uncertain or if Mirena is being used for mixed reasons, it’s always safer to be cautious and change it 5 yearly.
Useful resources:
https://www.fsrh.org/Public/News/Articles/FSRH-CEU-Statement–Extended-use-of-all-52mg-LNG-IUDs-for-up-to-eight-years-for-contraception.aspx?WebsiteKey=f858b086-d221-4a83-9688-824162920b1b
The above information is the professional opinion of Dr Kiran Atmuri, Specialist Obstetrician & Gynaecologist (FRANZCOG, MBBS, BCom/BSc, GCertClinTeach). While every effort is made to ensure information is accurate and reasonable, the information does not take the place of guidelines from professional bodies, an individual’s own research and consultation with a healthcare professional. There is no acceptance of liability for any injury, loss or damage caused by use of the information provided on this website.