Three GnRH agonists are currently available in France in clinical medicine with the indication: "Genital or extragenital endometriosis (from stage I to stage IV of the rAFS classification [4] )." The 2004 Cochran meta-analysis showed a significant improvement in the pain score in patients treated with GnRH compared with placebo, with the effect lasting 12 months after cessation of the medication, but few data are available on their advantages in the perioperative situation and in deep endometriosis. A. Audebert found an advantage to preoperative use of GnRHa in severe cases of endometriosis, with a significantly higher rate of patients having surgery that was considered optimal at the end of the intervention, both in terms of the endometriosis lesions and adherences. The benefits of GnRH treatment before medically assisted procreation are, however, supported by the literature.