The benefits of the Mannuelle ring, i.e. the levonorgestrel IUD, include good contraceptive effect, prevention of recurrence of endometrial polyps, etc. The side effects may mainly cause changes in menstruation, manifested as spotting bleeding, etc. The side effects of the Mannuelle ring include the release of levonorgestrel, which is the most effective contraceptive method. The levonorgestrel IUD, which contains a polydimethylsiloxane membrane in its structural composition, provides a slow, controlled release of levonorgestrel from the device, resulting in a very good contraceptive effect. This device is less damaging to the endometrium than the traditional copper-containing devices. It is used clinically for the treatment of dysmenorrhea, endometrial hyperplasia, and the prevention of recurrence of endometrial polyps. The main side effects are menstrual changes, manifested as spotting menstrual bleeding, reduced menstrual flow or even amenorrhea, and may also include abdominal pain, lumbago, and increased leukorrhea; the side effects may return to normal after removal of the device. After the IUD is inserted, patients should follow the doctor’s instructions and avoid sexual intercourse and tub baths for two weeks. If there is any obvious discomfort during the placement of the IUD, the patient should follow up with the doctor promptly.