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LNG-IUD (Hormonal Coil)

An Intrauterine System (IUS) is a small T-shaped plastic device that’s inserted into your womb (uterus).

Some of the commonly used hormone coils are Mirena, Levosert and Kyleena.

Key facts:

  • It is 99% effective at preventing pregnancy; less than one IUS / IUD user in 100 will get pregnant in one year 
  • Lasts between 3-5 years (Mirena 8 years and Levosert for 6 years) for contraception. and once removed your fertility goes straight back to what is normal for you 
  • The IUS releases a progesterone hormone to stop you getting pregnant 
  • After six months, periods usually become lighter, shorter and less painful or may stop altogether 
  • No STI protection 

New guidance on Mirena coil

Following a recent change in licensing and national guidance you can now use your Mirena coil for eight years for effective contraception.

If you are using Mirena as part of HRT the recommended duration of use remains 5 years.  See this statement from the Faculty of Sexual and Reproductive Health for more information here.

The licence for the other 52mg Levonorgestrel coils (Levosert and Benilexa) has not changed at the present time and these can still be used for 6 years for effective contraception, or 5 years as the progesterone component of HRT.

All these 52mg Levonorgestrel coils are also effective for the treatment of heavy menstrual bleeding, and if used as such and where contraception is not required they can remain in situ as long as they are providing effective symptom control.

Please note that if you were aged 45 or over when your 52mg Levonorgestrel coil was fitted then it will be effective as before until the menopause for contraception.  This includes Mirena and also Levosert and Benilexa.

How to use:

You’ll need to have the coil fitted at a clinic or by your GP.


Download our patient leaflet for more information.