title: The natural oestrogenic hormone oestradiol as a new component of combined oral contraceptives.
mesh_terms: D002986:Clinical Trials as Topic; D003276:Contraceptives, Oral / Q000009:adverse effects; D003277:Contraceptives, Oral, Combined / Q000009:adverse effects; D004958:Estradiol / Q000009:adverse effects; D005260:Female; D006801:Humans; D009640:Norethindrone / Q000009:adverse effects
chemical_list: D003276:Contraceptives, Oral; D003277:Contraceptives, Oral, Combined; D004958:Estradiol; D009640:Norethindrone