title: Natural oestrogens for oral contraception.
mesh_terms: D000568:Amenorrhea / Q000139:chemically induced; D002986:Clinical Trials as Topic; D003276:Contraceptives, Oral / Q000009:adverse effects*; D003278:Contraceptives, Oral, Hormonal / Q000009:adverse effects*; D004311:Double-Blind Method; D004341:Drug Evaluation; D004958:Estradiol / Q000009:adverse effects*; D004964:Estriol / Q000009:adverse effects*; D004997:Ethinyl Estradiol / Q000633:toxicity; D005260:Female; D006801:Humans; D008599:Menstruation Disturbances / Q000139:chemically induced; D009640:Norethindrone / Q000633:toxicity
chemical_list: D003276:Contraceptives, Oral; D003278:Contraceptives, Oral, Hormonal; D004997:Ethinyl Estradiol; D004958:Estradiol; D004964:Estriol; D009640:Norethindrone