Endometriosis is a chronic disease affecting 5-10% of women in reproductive age, showing recurrence after surgery at least in 20-50% after 5 years of follow-up. The long acting GnRH antagonist degarelix, which do not have the flare-up effect at the opposite of GnRH agonist and strongly suppress LH secretion and thecal cell activity may show a better effects on endometrial implants than GnRH agonist.