I too, have an enlarged thyroid and am currently taking O.O5mg of synthroid. I went to doctor, he said goiter is getting smaller. It has been about a month or a little more. Increased my thyroid Rx to 0.75mg. I have managed to lose 10 lbs on atkins. It took a while, to loose it. More than a month. I started it about the same time I started the Synthroid. Hope this helps, patti