Why would T3 only be better to use for some people than desiccated thyroid?

[Anisa]

I think I am one who can't convert T4 to T3, since T4 only treatment only made me worse. I'm now on 3 ½ grains Thyroid (217.5 mg daily). So why did the combination of syntetic medicines make me worse while NDT dosn't ?

Probably because the pharmacodynamics and pharmacokinetics of synthetic T3 and T4 are quite different from the NDT. That's why they are not only generally working differently from NDT in the human body, but they also works differently in different people.

One should not forget that while hormones in NDT are bound to thyroglobulin and other proteins / enzymes etc., synthetic T3 and T4 are "naked" molecules, T4 molecules are even made patentable by changing the molecular structure so those synthetic hormones are not longer exactly like the "real thing", because nature-identical synthetic hormones can not be patented, and therefore they can not bring significant profits for the pharmaceutical industry.

The "real" synthetic T3 is not patented... (only some different manufacturing processes are). One might therefore wonder whether it could be those relatively poor earnings of the synthetic T3, which are a contributing factor to the medical profession' "resistance" against offering their patients a combination therapy with Liothyronine? It would not be the first time that the medical profession favors the treatments they have shares in, right? I'm just asking ...