The reasons for less menstrual flow and black color are as follows: 1, black menstruation is caused by qi stagnation and blood stasis, and menstrual blood is accumulated in the uterus for a long time. 2. Women who over-diet will have less menstrual flow. 3, sulking or encountering important soul stimulation and psychological trauma can easily lead to less menstrual flow for girls. 4. Women with excessive work and rest are prone to less menstrual flow, because women are stimulated by cold during menstruation, which will cause excessive contraction of blood vessels in the pelvic cavity, which will lead to less menstrual flow and even amenorrhea. 5, less menstruation may also be endocrine reasons, such as abnormal secretion of various hormones or ovulation. Less menstrual flow is a kind of irregular menstruation, and sometimes it is accompanied by black color. Deer fetus is a traditional Chinese medicine specially used for regulating menstruation for women. It is known as "tribute to the palace, prescription for longevity and beauty", which shows that deer fetus is not cheap. According to Compendium of Materia Medica, deer fetus is a good medicine for gynecology, which has the functions of "invigorating qi and nourishing blood, nourishing kidney-yang, warming uterus, warming meridians and dispelling cold, activating qi and relieving pain, promoting blood circulation and regulating menstruation, and delaying menstruation", and it is the best for women to nourish and recuperate and delay aging. Lutai capsule is a new generation of female health care products made of deer fetus as the main raw material. Lutai capsule can nourish the ovary, make the ovary get a steady stream of nutrients, activate the ovary, promote the maturation of follicles in the ovary, and restore the youthful vitality of the ovary, thus restoring normal menstruation.