Synonyms: levothyroxine; l-t4; t4(hormone); o-(4-hydroxy-3,5-diiodophenyl)-3,5-diiodo-l-tyrosin; o-(4-hydroxy-3,5-diiodophenyl)-3,5-diiodotyrosine; tetraiodothyronine CAS: 51-48-9 EINECS: 200-101-1 Assay: 99% min. USP30 Packing: 1 kg /foil bag or tin. MF: C15H11I4NO4 MW: 776.87 Character: White Crystalline Solid.