Menstrual painkillers include indomethacin, ibuprofen, ketoprofen, etc. These are prostaglandin synthase inhibitors, mainly by inhibiting the activity of prostaglandin synthase, reducing the production of prostaglandins, thus preventing uterine contractions and spasms, reducing the pressure of the uterus and achieving the purpose of treatment, the clinical efficiency of treatment can reach about 90%. When taking this medicine, it is important to note that some people may have gastrointestinal reactions, manifested as nausea and vomiting. Women with peptic ulcers should not take it because it can cause bleeding peptic ulcers. Some people may also have allergic reactions after taking it, manifesting as itching all over the body, so if this symptom occurs, stop the drug immediately.