Thyroid UK
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thyroid labs in person without thyroid disease?

I have a somewhat strange question, but I hope nonetheless than someone will be able to answer it:

Did anyone have your thyroid function tested while your thyroid was still fully functional? If so, could you please tell me what your FTs looked like (I think that the TSH is supposed to be around 2?)

Unfortunately, I never had my thyroid function tested before a problem was suspected, so I have no idea what my FTs looked like while my thyroid was still working...

The reason I am asking is because I have been comparing my lab results on 5 grains of Armour and 5 grains of Erfa respectively (I always go to the lab 24 hours after taking NDT):

On Armour:

FT4 1.1 (ref 0.7-1.5)

FT3 2.9 (ref 2.8-3.8)

On Erfa:

FT4 1.2 (same ref)

FT3 3.7 (same ref)

Many would say that my labs looked better on Erfa as my FT3 levels were in the upper normal range...however, my question is: if they were that close to the upper normal range 24 h after taking the pills, that must necessarily mean that they were much higher on the previous day, even out of range? Is that really good?

I guess the tiny difference in FT4 levels is unimportant as FT4 is a slow-acting hormone...?

2 Replies

Thecat, TSH, FT4 and FT3 levels differ in healthy thyroid people. I've read euthyroid TSH is between 0.5-1.6 with African-Americans who have very low incidences of Hashimoto's averaging TSH 1.18. Euthyroid FT4 ad FT3 will be between half way and three quarters of the way through range on average.

Leaving 24hrs between last dose and blood draw means you can extrapolate FT3 by 20% so your 'true' circulating FT3 is 4.4 which is very slightly over range. If you don't feel overstimulated I wouldn't personally be too concerned, but if it bothers you try reducing 1/4 grain.


Thank you, Clutter:-)


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