I have been on Synthroid since 1991 and with all the trouble I had getting the dosage just right, I am not messing with it. I did try a few years ago to switch over to the Bovine Thyroid and it didn't work, so unless my endocrinologist changes me, I am staying with synthroid. Just taking thyroid will not help you lose wt necessarily. In 1996 I lost 47 lbs. in 5 months just eating low fat, the thyroid situation was the same then, so I know it can be done. Usually the full blood profile will catch it, if it includes a TSH. I tell you, hypothyroidism is miserable but so is getting TOO much. I think most of us with this problem will just lose slower and we will just have to accept it in order to feel better