The Mannuelle ring is clinically known as levonorgestrel intrauterine device (IUD) system. The side effects of levonorgestrel intrauterine device (IUD) system usually disappear in about 2-3 months, and the exact time is related to the patient’s physical condition. Levonorgestrel IUD placement may cause prolonged bleeding time, irregular bleeding, amenorrhea, scanty menstruation and other side effects, usually disappears in about 2-3 months, if the adverse reaction has been continued, need to consult a doctor in time. Levonorgestrel IUD system can be used for contraception and idiopathic menorrhagia, but it cannot be placed in patients who are pregnant and suffering from pelvic inflammatory disease, endometritis, cervicitis, malignant uterine lesions and other diseases. If the side effects of levonorgestrel IUD do not go away for a long time, it is also necessary to go to the hospital in time to avoid worsening of the symptoms.