GNRH1 and endometriosis: A Cochrane systematic review comparing the effects of various treatments for endometriosis to those of gonadotrophin‐releasing hormone analogues (GnRHas) on the bone mineral density (BMD) of women with endometriosis concluded that between the groups receiving GnRHa and the groups receiving Danazol, there was a significant difference in percentage change of BMD after 6 months of treatment, with the GnRH analogue producing a reduction in BMD from baseline and Danazol producing an increase in BMD (Sagsveen et al. 2003).