I have been as high as 175mg. When I asked about this at hospital. The Dr checked my levels via computer and sent a letter to my Dr. I was immediately reduced to 125. Then put up to 150 now had blood test so it will change.One important thing is take 30/1 hr before breakfast and other tablets for the tablet to work the best.
Drs hit and miss i think. Best to see a specialist who deals with thyroid.
Best timing to take Levothyroxine?
I've finally been given T3 to try after all these years, but I do have a worrying question.
T3 at last. Help please.
Feeling confused - latest blood results 
