Testosterone Replacement Therapy (TRT)
The reference range for Testosterone (the “healthy” amount for a man to have circulating in his blood stream) is extremely general, and ranges from 270ng/dL all the way up to 1070 ng/dL.
This means for the average idiotic doctor who knows nothing about male hormones (but will readily prescribe Estrogen to females like candy), they will tell a 21 year old male they are healthy if their total Testosterone is at 270 ng/dL.
I don't think I need to tell you that there is a huge difference between 270 ng/dL and 1000+, but if I do, then let's just put it this way.
It could be the difference between you walking around functioning with a high quality of life, and you walking around with a dysfunctional penis, a non-existent sex drive, and extreme difficulty putting on muscle and burning fat.
The true purpose of TRT is to use exogenous Testosterone to achieve a Testosterone level that is in the middle of that range, or ideally on the high end of that range.
The high end being commonly referred to as “high-normal”, as it's the high end of what a normal functioning male in their prime would endogenously produce themselves if they had top tier genetics.
How many genetic phenoms are there out there naturally pumping out 1000 ng/dL test levels courtesy of their balls and not relying on exogenous T to hit that blood serum concentration?
Not many.
After you hit 30 years old, your Testosterone levels will start to naturally decline by 1% per year.
Each year you will inevitably lose more of your natural hormone production, until eventually you are on the low end of the reference range, or have fallen out of it entirely, which would THEN at that point qualify you for TRT as far as most ignorant doctors are concerned.