Ethinylestradiol (EE), the active form of<unk> .<unk>  is a biologically inactive prodrug of ethinylestradiol to which it is demethylated in the liver (via O-Dealkylation) with a conversion efficiency of 70% (50 μg of<unk>  is pharmacokinetically bioequivalent to 35 μg of ethinylestradiol). It has been found to possess 0.1 to 2.3% of the relative binding affinity of estradiol (100%) for the estrogen receptor, compared to 75 to 190% for ethinylestradiol. The elimination half-life of<unk>  has been reported to be 50 minutes. The elimination half-life of the active form of<unk> , ethinylestradiol, is 7 to 36 hours. The effective ovulation-inhibiting dosage of<unk>  has been studied in women. It has been reported to be about 98% effective at inhibiting ovulation at a dosage of 75 or 80 μg/day. In another study, the ovulation rate was 15.4% at 50 μg/day, 5.7% at 80 μg/day, and 1.1% at 100 μg/day.
Mestranol
Hexestrol
Gestodene
Fosfestrol
Moxestrol
Allenestrol
Dimestrol
Dienestrol