Taking ibuprofen every month for menstrual cramps may have certain side effects such as nausea, vomiting, loss of appetite and other gastrointestinal reactions. However, ibuprofen is safe and generally does not cause very serious side effects when taken as prescribed by the doctor. Patients with severe liver and kidney insufficiency, patients with peptic ulcers, and patients with allergy to ibuprofen should not take ibuprofen during dysmenorrhea. Altered prostaglandin levels are considered to be the root cause of primary dysmenorrhea in women, and ibuprofen, as a non-steroidal anti-inflammatory drug and also a prostaglandin synthase inhibitor, can reduce prostaglandin production and prevent uterine contractions and spasms by inhibiting the activity of prostaglandin synthase, thus reducing or eliminating dysmenorrhea with good overall therapeutic effect. Ibuprofen reaches its peak blood concentration 2-3 hours after taking the drug and has a long-lasting effect, so it is recommended for women with dysmenorrhea to use it the day before their menstruation for better results. However, some women with dysmenorrhea have secondary dysmenorrhea, caused by diseases such as endometriosis and adenomyosis. Such patients should consult a doctor in time to treat the primary disease, and the dysmenorrhea can improve naturally, instead of using ibuprofen alone for pain relief.