David,
I have been taking Synthroid for several years prior to getting cancer, and still take it, with the levels being monitored every 6 months.
Unfortunately, I am still very fatigued 2 1/2 months post Tx. I guess I was expecting too much to feel energetic so soon, so I will carry on like everyone else!

Betty

Squamous Cell Carcinoma of tongue, stage II due to size >3mm, nothing seen in neck on CT scan. Radiation started in Jan 07. Completed 2/26/07. Recurrance confirmed 8/07.