Norethisterone (3-ketoetynodiol), the active metabolite of<unk> .<unk>  is virtually inactive in terms of affinity for the progesterone and androgen receptors and acts as a rapidly converted prodrug of norethisterone, with<unk>  occurring as an intermediate. Upon oral administration and during first-pass metabolism in the liver,<unk>  is rapidly converted by esterases into<unk> , which is followed by oxygenation of the C3 hydroxyl group to produce norethisterone. In addition to its progestogenic activity,<unk>  has weak androgenic activity, and, unlike most progestins but similarly to norethisterone and noretynodrel, also has some estrogenic activity. The pharmacokinetics of<unk>  have been reviewed.
Etynodiol diacetate
Bolandiol dipropionate
Tetramethyl bisphenol F
Chlormerodrin
Oxabolone cipionate
Beta-Zearalenol
Tienilic acid
Diethylstilbestrol disulfate