title: A flexible low dosage system of oral contraception.
mesh_terms: D000293:Adolescent; D000328:Adult; D004338:Drug Combinations; D004341:Drug Evaluation; D004997:Ethinyl Estradiol / Q000008:administration & dosage / Q000494:pharmacology*; D005040:Ethynodiol Diacetate / Q000009:adverse effects / Q000494:pharmacology; D005260:Female; D006801:Humans; D008535:Megestrol / Q000009:adverse effects / Q000494:pharmacology; D008598:Menstruation / Q000187:drug effects*; D008599:Menstruation Disturbances / Q000139:chemically induced; D008875:Middle Aged; D011247:Pregnancy
chemical_list: D004338:Drug Combinations; D004997:Ethinyl Estradiol; D005040:Ethynodiol Diacetate; D008535:Megestrol