I had thyroid cancer and had half of my thyroid removed. Over the years the other half has atrophied into basically nothing. My doctor tested my thyroid levels yesterday and they were too low. She is lowering my Synthroid dose from 112 micrograms to 100 micrograms. I don't really understand all the science behind it but I do know this is the correct move at least it is for those that still have a thyroid gland. Is it still the right move when I do not have a thyroid gland?