Sulfates are the major circulating conjugates of ethinyl estradiol and glucuronides predominate in urine. The first oxidative metabolite is two-hydroxy ethinyl estradiol, shaped because of the CYP3A4 isoform of cytochrome P450. Portion of the very first-pass metabolism of ethinyl estradiol is believed to occur in gastrointestinal mucosa. Ethinyl es