All drugs are intentionally toxic. CZ research

Why More Women Die of Heart Disease healthy4life

…dez...

This is a strong indication that you may have low adrenal output
low cortisol.

Are you still experiencing this paradoxical reaction? If so, you may not be converting T4 to T3 but T4 to RT3 instead.
This could be caused by many things, such as low iron, low (or abnormally high) cortisol, calorie restriction, excess inflammation, chronic or acute illnesses, infections or even emotional stress.

http://www.autoimmunemom.com/hashimotos-thyroid/t3-reverset3-function-importance.html
http://www.stopthethyroidmadness.com/reverse-t3/

Here are the labs you'd want to do to get better insight into what is going on in your body:
http://www.stopthethyroidmadness.com/recommended-labwork/

This is helpful for calculating the RT3-ratio:
http://www.stopthethyroidmadness.com/rt3-ratio/

&(If you find you do have the RT3 problem,) this is a great support group:
https://groups.yahoo.com/neo/groups/RT3_T3/info

The recommendation for clearing RT3 is to go on Liothyronine (synthetic T3). I know cz is somewhat against synthetics (well, pharmaceutical drugs in general) but if your body is converting T4 into RT3, natural desiccated thyroid (which contains T3 but also T4), may not help you as much as taking T3 only will.