First, dysmenorrhea can be used. But if you take it blindly, the effect is relatively poor. Second, fennel is sweet, pungent and warm, and has the effects of warming meridians and dispelling cold, promoting qi circulation and relieving pain, invigorating stomach, broadening chest, detoxifying and eliminating dysentery. However, those with yin deficiency and excessive fire are prohibited. The general dosage is 3-8g. Third, this medicine can be boiled with strong water and simmered for 30 minutes.