Sulfates are the foremost circulating conjugates of ethinyl estradiol and glucuronides predominate in urine. The principal oxidative metabolite is two-hydroxy ethinyl estradiol, formed via the CYP3A4 isoform of cytochrome P450. Component of the main-go metabolism of ethinyl estradiol is considered to come about in gastrointestinal mucosa. Ethinyl e