Levonorgestrel-releasing intra-uterine systems as female contraceptives.

INTRODUCTION: The availability and use of long-acting reversible contraceptives (LARCs), such as levonorgestrel intrauterine systems (LNG-IUSs), have increased in recent times. AREAS COVERED: The authors provide a narrative review of the LNG-IUSs currently available worldwide as female contraceptives (LNG-IUS 13.5, 19.5 and 52 mg). Specific features of the devices and their parameters of efficacy and tolerability were considered as outcomes. EXPERT OPINION: The one-handed 3.8-mm-diameter inserter of LNG-IUS 13.5 mg and 19.5 mg may be particularly suitable in nulliparous women. While LNG-IUSs 13.5, 19.5 mg and LNG 52 mg should be used by women simply looking for an effective contraceptive method for up to 3, 4 or 5 years, LNG-IUS 52 mg has also been approved for the treatment of heavy menstrual bleeding and endometrial protection during hormone replacement therapy. LNG-IUS 52 mg is ideal for women who are experiencing a certain hyperestrogenic hormonal environment, with heavy menstrual bleeding due to hormonal imbalances, adenomyosis or fibroids, in the case of symptomatic endometriosis or for endometrial protection during hormone estrogenic replacement therapy in non-hysterectomized women.