Soybeans and soy-based substances in our food contain soy isoflavones, which are rich in phytoestrogens and when consumed can make menstruation more regular and play a role in regulating menstruation. The menstrual cycle is regulated by the function of the ovaries and generally has a constant cycle, dominated by estrogen. During the first half of menstruation, the growth of the endometrium is mainly regulated. During this period, the endometrium changes in the proliferative phase, and after ovulation, under the combined action of estrogen and progesterone, the endometrium changes in the secretory phase. When estrogen and progesterone retreat, causing the onset of menstruation, the consumption of soybeans and soy products can increase the level of estrogen in the human body, allowing the endometrium to have better proliferation and secretion, allowing women to have a more regular menstrual cycle.