How much T3 and T4 do we make Naturally ?
You hear a lot of various opinions about how much T4 and T3 you should take – if you are going to take it
To me that discussion begins with an understanding that the Thyroid Axis is subject to a Negative feedback loop just like the HPTA and the IGF-1 Axis
So when we add T, our Natural Production is impacted
The same is true for rHGH you lose your night pulse of Natural HGH when you add exogenously, or at least if you raise IGF-1 high enough to trigger the negative feedback
So that is step 1. Understanding that external source is not ” extra” it’s instead of at least up to the point that you have replaced what you had the day before to started using T3 or T4, yes after that is additional..
Step 2 is asking so how much T4 and T3 do we make naturally?
For the average-sized person.. read that as ” Citizen Joe”
Around 100mcg T4
Around 29 mcg T3
That means 100mcg T4 and around 29mcg of T3 would be akin to TRT for your Thyroid ( once the negative feedback loop kicks in )
From this understanding, we can start the discussion about T3 and T4 supplementation.