Sulfates are the major circulating conjugates of ethinyl estradiol and glucuronides predominate in urine. The main oxidative metabolite is two-hydroxy ethinyl estradiol, fashioned because of the CYP3A4 isoform of cytochrome P450. Section of the first-move metabolism of ethinyl estradiol is thought to occur in gastrointestinal mucosa. Ethinyl estrad