I seems that the normal range is all over the place. It may go according to age. I've been on T shots for several months and I am up to 250 which is the very bottom of the range according to my doc. I will be getting the shots twice a month now and up the dose a bit. I must say I am doing better than I was but the doc has also been adjusting my thyroid dosage. Getting everything just right is touchy as they all together and effect each other. At least I think I am on the right track.