title: Oral contraception using a sequential method. A clinical investigation.
mesh_terms: D000085:Acetates; D000328:Adult; D001835:Body Weight / Q000187:drug effects; D002986:Clinical Trials as Topic; D003075:Coitus / Q000187:drug effects; D003276:Contraceptives, Oral / Q000008:administration & dosage* / Q000009:adverse effects; D004997:Ethinyl Estradiol / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007785:Lactose; D008535:Megestrol / Q000008:administration & dosage; D008598:Menstruation / Q000187:drug effects; D008722:Methods; D010919:Placebos; D011247:Pregnancy; D011278:Pregnanes / Q000008:administration & dosage*; D011372:Progestins / Q000008:administration & dosage*; D013607:Tablets; D013997:Time Factors
chemical_list: D000085:Acetates; D003276:Contraceptives, Oral; D010919:Placebos; D011278:Pregnanes; D011372:Progestins; D013607:Tablets; D004997:Ethinyl Estradiol; D008535:Megestrol; D007785:Lactose