Elaine, I am one who couldn't take Synthroid without becoming hyperthyroid/overmedicated. Because that's all my then-MD would prescribe, I had to find answers elsewhere. The next MD I saw put me on Armour, and I never had a problem with medication after that. It seems to work more "gently" for me, not causing spikes that make levels unstable. Armour is a natural combination of T4/T3... not only the T4 that you take now. Only a minority of MDs (the smart ones ;) ) are willing to prescribe it, even though millions of patients feel best with some T3 added to the mix.

At the very least, your MD should be trying all the brand names of T4 available in the arsenal. Besides Synthroid and Levoxyl, the other T4 drugs available in the US are Unithroid, Levothroid, and Levo-T. There are many generics, too. Any one of those might work better than the two you've tried so far, because there can be huge differences in the way any particular body makes use of the chemical makeup differences that comprise them.