lab tests

[terebol]

Hi, What is the lab test to learn if one is converting T4 to T3? I am on NDT so I expect I wouldn t need to be tested, but only for individuals on synthetic T4--correct? My curiosity is because I am asking for a friend who is not prone to researching. Thanks!

[radd]

terebol,

Some members advise you can only obtain results that confirm impaired conversion when medicating Levothyroxine only, and having both FT4 & FT3 tested at the same time. 

I’m not sure why this is suggested as even when medicating T4 and T3 (as in NDT), should FT3 levels remain stubbornly low in comparison to FT4, this too would indicate a poor conversion ability. 

It is when we start bringing in (possibly unneeded) higher amounts of medicated T3 or excess T4 that the waters become muddied, making assessment difficult. 

Remember there are many reasons for poor conversion and even those with genetic impairments, can often see improvements through optimising nutrition and taking steps to reduce any bodily inflammation. 

[terebol in reply to radd]

Thank you--another layer of mystery!

[diogenes Remembering in reply to terebol]

For NDT this isn't the answer. NDT has a T4/T3 ratio of about 4/1. If you take NDT, in the appropriate amount, you can gain "normal" FT3 simply by direct dosage.. If you take T4 only, then T4-T3 conversion is important. If you are a poor converter, the FT4/FT3 ratio will show it as being about 4.5/1 or worse. Taking NDT is rather like taking combination therapy except that the ratio in poorer converters can be different. A FT3 level suitable for your needs is the best target: FT4 not so important, and TSH definitely not.

[terebol in reply to diogenes]

Thank you for the clarification. I know that TSH is not important for dosing but the docs, still, like to run the numbers. Since NDT has the approximation of 4:1 when an individual is on synthetics, they should shoot for the same to get out of the starting gate? I, truly, am, trying to get this pegged down for a friend who does not research. Thank heavens for NDT as I tried the synthetic route 10mos & it didn't work for me. Thanks!