Diphaston-D6; Dufaston-D6; Duphaston-D6; Duvaron-D6; Dydrogesterone-D6; Gestatron-D6; Gynorest-D6; Hydrogesterone-D6; Isopregnenone-D6; NSC 92336-D6; Prodel-D6; Retro-6-dehydroprogesterone-D6; Retrone-D6; 6-dehydro-Retroprogesterone-D6; Terolut-D6,Dydrogesterone Stable Isotopes