Menstruation is caused by the shedding of the endometrium resulting in vaginal bleeding. Before menstruation, the estrogen and progesterone levels in the body drop to their lowest values and cannot maintain the state of the endometrium resulting in the shedding of the endometrium. To make menstruation clean, the estrogen and progesterone levels in the body need to fall normally and the endometrial lining will be shed more completely. Since the estrogen and progesterone secreted by the ovaries receive the control of the hypothalamus-pituitary gland and change cyclically, there is no need for human intervention for menstrual blood elimination if menstruation is regular. For women with prolonged menstrual periods, if it is considered to be caused by a slow retreat of progesterone, progesterone capsules or dextran tablets can be considered to regulate the treatment in the second half of the menstrual cycle. According to Chinese medicine, women with slow menstruation are mostly caused by stagnation of blood and qi in the body, so it is recommended to take herbs that activate blood circulation and eliminate stasis to promote clean menstruation, such as motherwort, angelica and safflower.