title: The difficulties of double blinding.
mesh_terms: D004311:Double-Blind Method; D015914:Estrogen Replacement Therapy / Q000009:adverse effects; D005260:Female; D006801:Humans; D010349:Patient Compliance; D010919:Placebos; D016032:Randomized Controlled Trials as Topic
chemical_list: D010919:Placebos