Hi, looking at my stash of unused thyroid medication I have only just noticed - it's only taken me 20 years!!! - that my 50mcgs of t4 are simply levothyroxine, but many of my old 25mcgs are levothyroxine sodium. Does anyone know what the chemical difference is? It is funny because I always asked for that brand of 50mcgs as I found it suited me better, it is by activism whereas I felt more symptomatic if taking the other ones which taste salty. Anyone else had that experience?