I am having difficulty with my thyroid medications. It doesn't seem to matter if I am on Synthroid or NDT. I feel so tired and zombie like after I take thyroid medicine. I can feel the fatigue kick in about a half hour after taking it. What could be causing this? Has anyone else had issues with fatigue and becoming ill after taking a thyroid dose? Please help me if you can. Seems I'm sick without my meds and sick on them too. It just sucks living like this.