I have Hashimotos, and take 100mcg and 25mcg Thyroxine daily. For reasons that will take far too long to explain, I filled two difference prescriptions at two different chemists. One chemist gave me 100mcg and 25mcg from two difference pharmaceutical companies. I have been taking these for approx a week, and have started to feel ill again, after being stable for a number of years. When I looked at the boxes of tablets I realised why! The other chemist gave me tablets both from the same pharmaceutical company, and which I have taken most of since being diagnosed, I have taken these for the last couple of days, and the symptoms have abated and I feel fine again! But how can this be? Surely the drug strength should be the same in ALL tablets, immaterial of the manufacturer? Has this happened to anyone else? Merry Christmas!!