Metronidazole can be taken during menstruation, and the patient may have gynecological inflammation that requires anti-inflammatory treatment. Menstruation can be treated with anti-inflammatory drugs or anti-inflammatory injections due to pelvic congestion. For women with pelvic inflammatory disease, anti-inflammatory treatment is sometimes recommended during menstruation, using anti-inflammatory injections or oral metronidazole. This is because metronidazole is an anti-anaerobic anti-inflammatory drug that is more effective for gynecological inflammation. Patients with trichomonas vaginitis also need to be treated with metronidazole, which can be taken orally during menstruation, and need to be treated together as a couple. There is no adverse effect of taking metronidazole during menstruation, and it is more effective in the treatment of female pelvic inflammatory disease. Some patients may have gastrointestinal reactions, such as nausea and vomiting, after using metronidazole, which may be confused with menstrual discomfort, and the doctor needs to choose the drug according to the specific situation.