Gestrinone (R2323) is a synthetic steroid hormone with an inhibitory value of 43.67 μM for smooth muscle tumors and has potential for use in endometriosis research.Gestrinone is a click chemistry reagent. It contains an Alkyne moiety that can undergo a copper-catalyzed azide-alkyne cycloaddition reaction (CuAAc) with molecules containing an Azide moiety.