If the patient still has vaginal bleeding after taking kynurenine, it suggests the following two possibilities: First, the dose taken is incorrect. If it is used to stop bleeding, it needs to be used 3 times a day for the first 3 days, and then changed to 2 times/day after the bleeding stops, and then changed to a maintenance dose for 2 weeks after 7 days of use, and then stopped. If the patient takes a small dose for the first time, or in the process of reducing the dose is not appropriate, abnormal bleeding is likely to occur. Second, the patient has organic lesions, norethindrone tablets to stop bleeding effect is not good. Kynurenine tablets are suitable for abnormal uterine bleeding caused by endocrine disorders, but not for bleeding caused by organic lesions, such as adenomyosis, endometrial polyps, cervical and endometrial tumor lesions. In clinical practice, the use of hormonal drugs to stop bleeding requires that the effect be seen within 8 hours and the bleeding basically stops within 24-48 hours. If the bleeding still does not stop after 96 hours or more, it is necessary to consider changing the diagnosis and doing tests such as scraping to clarify the diagnosis, as well as changing the treatment plan.