PGR and endometriosis: Denogestrel is a derivative of 19-nortestosterone, which has been shown to bind highly selectively to the progesterone receptor with moderate estrogenic inhibition, and has strong antiproliferative, antiangiogenic and anti-inflammatory properties on endometriosis implants, while having some antiandrogenic activity, but no significant estrogenic, glucocorticoid or salicorticoid activity, and little effect on metabolic parameters (11).