title: [Single blind method of ENN tablets, a single-blind method].
mesh_terms: D000293:Adolescent; D000328:Adult; D000568:Amenorrhea / Q000188:drug therapy; D002986:Clinical Trials as Topic; D004357:Drug Synergism; D004412:Dysmenorrhea / Q000188:drug therapy; D005260:Female; D006801:Humans; D008656:Mestranol / Q000627:therapeutic use*; D008875:Middle Aged; D009641:Norethynodrel / Q000627:therapeutic use*; D010919:Placebos; D014592:Uterine Hemorrhage / Q000188:drug therapy*
chemical_list: D010919:Placebos; D009641:Norethynodrel; D008656:Mestranol