This document summarizes the role of Mirena (LNG IUS) in treating menorrhagia (heavy menstrual bleeding). Mirena is a T-shaped intrauterine system that releases levonorgestrel locally in the uterus. It is an effective treatment for menorrhagia, reducing bleeding more than oral medications. Studies show Mirena improves quality of life for those with heavy periods and can prevent the need for hysterectomies in many cases. Mirena is also cost-effective compared to other treatments like surgery. The document reviews various studies on Mirena's effectiveness and emerging evidence for additional uses like treating endometriosis or as contraception.