FFPRHC Guidance (April 2004). The levonorgestrel-releasing intrauterine system (LNG-IUS) in contraception and reproductive health.

Journal of Family Planning and Reproductive Health Care 2004: 30(2) What is the levonorgestrel-releasing intrauterine system? This Guidance provides recommendations and good practice points regarding the use of a levonorgestrelreleasing intrauterine system, the accepted abbreviation for which is LNG-IUS. The use of a copper-bearing intrauterine device (IUD) has been covered in previous Faculty Guidance.1 The LNG-IUS has been licensed as a contraceptive in the UK since May 1995. Recent National Statistics suggest the LNG-IUS is used by only 1% of women aged 16–49 years who are currently using a method of contraception.2 The LNG-IUS now also has a licence for the management of idiopathic menorrhagia3 and may therefore be used by women who do not require contraception. The LNG-IUS has a T-shaped, plastic frame with a reservoir on the vertical stem containing 52 mg (milligrams) levonorgestrel (LNG) mixed with polydimethylsiloxane. A rate-limiting membrane allows LNG to be released into the uterine cavity at a constant dose of 20 mg (micrograms) per day. Devices releasing lower doses of LNG are not currently licensed in the UK. This Guidance summarises evidence for the use of the LNG-IUS in all aspects of contraceptive and reproductive health.