title: Substitution of levothyroxine products.
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000188:drug therapy; D007880:Legislation, Drug; D013810:Therapeutic Equivalency; D013974:Thyroxine / Q000592:standards* / Q000627:therapeutic use; D014481:United States
chemical_list: D013974:Thyroxine