Estradiol 3-sulfate is a sulfated form of the steroid hormone 17β-estradiol , and is common in fetal plasma and in the breast tissues of patients with mammary carcinoma. Sulfated estrogens, including estradiol 3-sulfate, can be converted back to the parent compound by sulfatases. Estradiol 3-sulfate 17β-glucuronide is a metabolite of estradiol 3-sulfate that has been modified by a UDP-glucuronosyltransferase. Glucuronidation of estrogens enhances their utilization by anion transporters, most commonly leading to excretion in urine and bile.