Log in
Thyroid UK
93,604 members107,636 posts

daily requirement of t3 and t4?

Just curious, as I am experimenting to find the right dosage of NDT: does anyone know how much (more or less) T3 and T4 a human thyroid produces each day? I have been told, and I have read, over and over again, that pigs (and most other animals) produce more hormones than humans, for the simple reason that their metabolism is much faster (which is supposedly also why they don't live as long as we do), so we really cannot compare ourselves to them...however, I have been wondering if inadequate T4 to T3 conversion does not mean that some human beings might need as much T3 and T4 daily (=NDT) as some animals produce...?

5 Replies

anna69 ,

Like everything else in the thyroid world. Things ain't so simple.

We need to understand in depth things like the efficiency with which these hormones are handled. There are processes which allow recycling of, for example, T4, through sulphation, releasing to the gut, then re-absorption. You need to know how that process compares between species - not just how much each produces.

Some people, and Sandy12 is a knowledgeable member on this, are resistant to thyroid hormone. In extreme cases the amounts needed are very high.


Thank you! I am asking because I seem to do best on 6 grains (360 mg) of Erfa thyroid...which completely suppresses my TSH and gives me FT3 levels of 3.8 (ref 1.7-3.9)...



Perhaps your body is unusually capable of processing excess thyroid hormone so that it is safely excreted?

We have over the years seen extremes at both ends of the spectrum - some taking far less, some far more, than most of us would have thought possible.


Anna69, Estimates of average normal secretion for euthyroid humans are 94-110 µg T4 and 10-22 µg T3 daily.


I'm not sure it's worth comparing hypothyroid patients with euthyroid individuals, or euthyroid humans with animals. We all need what we need and averages inevitably work out as too little for some, and too much for others.


Thanks! See my reply to Helvella above!


You may also like...