Sulfates are the major circulating conjugates of ethinyl estradiol and glucuronides predominate in urine. The first oxidative metabolite is two-hydroxy ethinyl estradiol, formed through the CYP3A4 isoform of cytochrome P450. Portion of the main-go metabolism of ethinyl estradiol is thought to occur in gastrointestinal mucosa. Ethinyl estradiol may … Read More