GNRH1 and endometriosis: Results from clinical trials have indicated that dienogest provides effective pain relief equivalent to GnRH agonists, a reduction of endometriotic lesions, and a favorable safety and tolerability profile in patients with endometriosis (Cosson et al. 2002, Momoeda et al. 2009, Köhler et al. 2010, Strowitzki et al. 2010a,b, Felice et al. 2012).