Narfarelin is used to treat endometriosis, inflammation, and cysts, and its effect is mainly by inhibiting the hypothalamic-pituitary-ovarian axis, resulting in a low estrogen state in the body, causing ectopic endometrial atrophy. In addition, nafarelin can also be used to treat central precocious puberty. Endometriosis is an estrogen-dependent condition in which ovarian hormones are required for ectopic endometrial growth.