Estriol Synonyms: oestriol; 1, 3, 5(10)-Estratriene-3, 16a, 17b-triol CAS: 50-27-1 EINECS: 200-022-2 Assay: 97.0%-102.0%, USP30. Packing: foil bag or tin. Delivery: Express courier. Character: White crystalline powder. Usage: A metabolite of Estradiol. An estrogenic metabolite considerably less potent than the hormone Estradiol. pharmaceutical material, Steroid hormone, estrogen. Standards:USP27