5b-Pregnane-3,20-dione;a metabolite of progesterone, formed in relatively small quantities, that occurs in 5a and 5b isomeric forms. ... (05 Mar 2000) ... 
Type: Term Pronunciation: preg′nān-dī′ōn Definitions: 1. A metabolite of progesterone, formed in relatively small quantities, that occurs in 5α and 5β isomeric forms.