I have been taking for Nearly 5 months now , I cannot increase more than 1.5 grains without getting extremely itchy and hot with hives around my neck and back . I thought ok to stay at 1.5 .. ( equivalent to 150 Levo ? ) I had a test a 2 months ago .. TSH was 1.94 and my T3 was still quite low . My problem is my severe muscle pain has come back , it is pretty much everywhere .i used to get the same pain taking Levo , I couldn't increase higher than 75, if I did I got the same hot/ hives . I am taking 1000 sub b12 and complex . I havnt tested my vIt d for a while ,, last time it was ok ....not sure what to do now , quite disappointed ... feel might as well go back to Levo ,,, as Dr doesn't know I've changed !