How much IGF-1 in circulation normally?

[TobyJ]

I posted this on another forum, but didn't get too many replies. This IGF forum seems pretty active, so I figured I'd try it here...

I was looking over some blood work, and if my math is right, the amount of IGF in normal circulation, and it would seem, the amount produced naturally, might be quite a bit higher than I once thought.

My IGF-1 was 190 ng/ml (nano gram per milliliter), and this was in the normal range. If the average human body contains 5L of blood (5000 ml), that would give me 950,000 nanograms of IGF-1. Converting nanograms to micrograms (divide by 1000) give us 950 mcg circulating in my blood.

What I don't know is how much of this is free, and how much is bound. And, since BBers use the L3 variety, that doesn't get tied up in the binding protein, the 40-100mcg being injected PWO might still be a huge amount of free IGF.

But, it does seem to debunk the often held belief that the human body only makes around 1-2mcg of IGF-1 per day.

Toby

 

[DeltaNiner]

This is new to me and I thank you for posting this bro. It was my understanding that natural IGF levels for adult males are in the 1mcg range. I think several endocrinologists or those with medical friends seemed to corroborate this. If what you said is correct then that certainly changes a couple things.