Sulfates are the key circulating conjugates of ethinyl estradiol and glucuronides predominate in urine. The main oxidative metabolite is 2-hydroxy ethinyl estradiol, fashioned by the CYP3A4 isoform of cytochrome P450. Portion of the very first-pass metabolism of ethinyl estradiol is thought to come about in gastrointestinal mucosa. Ethinyl estradio