Androgen and progestin; hydrogenation product of gestrinone, q.v. Discovery, synthesis, LC/MS/MS and GC/MS determn in urine: D. H. Catlin et al., Rapid Commun. Mass Spectrom. 18, 1245 (2004). Hormonal properties: A. K. Death et al., J. Clin. Endocrinol. Metab. 89, 2498 (2004). In vitro metabolism study: J.-F. Lévesque et al., Anal. Chem. 77, 3164 (2005).