Urinary oestrogens in pill-users may be artefacts.
D003276:Contraceptives, Oral / Q000378:metabolism*; D004967:Estrogens / Q000096:biosynthesis / Q000652:urine*; D005260:Female; D006801:Humans; D009640:Norethindrone / Q000378:metabolism
D003276:Contraceptives, Oral; D004967:Estrogens; D009640:Norethindrone