Alaurelin (gonadotrophin releasing hormoneanalogue (GnRH-A), also known as protamide, is a nine-peptide analogue of synthetic gonadotropin-releasing hormone (GnRH), which is 15 times more potent than the parent body. At the initial stage of medication, it can stimulate the pituitary gland to release luteinizing hormone (LH) and follicle-stimulating hormone (FSH), causing a transient increase in ovarian-derived steroid hormones; Repeated medication can inhibit the release of LH and FSH from the pituitary gland, reduce the level of estradiol in the blood, achieve the effect of drug ovaries, and regulate the expression of related oncogenes ras, neu and myc of endometrial cancer. Clinically, it is mainly used to induce ovulation, treat infertility caused by abnormal ovarian function, endometriosis and uterine fibroids, and improve pregnancy rate.