The second day of menstruation is a good time for the production and increase in the number of oocytes. The second day of menstruation is the best time for the production of oocytes, and the use of descending tone injections is conducive to the production and increase in the number of oocytes, and promotes the pituitary gland to secrete more oocytes. At the same time, it can actively determine the time of human chorionic gonadotropin and the time of egg retrieval, creating favorable conditions for artificial egg retrieval. Down-regulation is a way to regulate the hormone level of the body through drugs to obtain mature and sufficient number of eggs, mainly to prevent the loss of follicles caused by ovarian ovulation disorder. Some patients may experience adverse symptoms such as nausea and vomiting, weight gain and high blood pressure after taking down-regulation injections, and in severe cases, they may also suffer from emotional instability and sleep disorders. In clinical practice, when patients want to take down-regulation injections, it is recommended to do so under the guidance of a doctor to avoid the adverse consequences of wrong injections.