Labeled 4-Pregnen-20a-ol-3-one (P712215). 4-Pregnen-20a-ol-3-one is the main metabolite of Progesterone. Studies shows regulation of estrogen receptor levels in breast cancer by 4-Pregnen-20a-ol-3-one and other progesterone metabolites.Form:Off-White SolidMelting Point:166-169°CSolubility:Chloroform, Methanol