The benefits of the Mannuelle Ring, or Levonorgestrel IUD, include that it can be used for contraception, as well as for the treatment of abnormal uterine bleeding, adenomyosis, etc.; the disadvantages include that it can cause decreased menstrual flow, abnormal vaginal bleeding, and lower back pain, among other things. The levonorgestrel IUD system can be used primarily for female contraception, as well as to reduce abnormal uterine bleeding caused by abnormal thickening of the uterine lining, and also to reduce the level of pain in adenomyosis, endometriosis, and other conditions by inhibiting the growth of the uterine lining. In addition, it also reverses some of the atypical endometrial hyperplasia. The main disadvantages include the possibility of back pain, abdominal pain and increased leukorrhea after the IUD; some women may experience abnormal vaginal bleeding after the IUD. In addition, due to the release of progesterone from the IUD, the endometrium may become thin and atrophic, resulting in low menstrual flow and possibly even amenorrhea, but it is often reversible and can be restored after removal of the IUD. It is recommended to consult a professional doctor for standardized diagnosis and treatment before applying the IUD.