Comment by Roark66

>A good rule of thumb in biology and particular any kind of hormone production and balance is "use it or lose it" - if you start regularly receiving something externally, internal production will scale back and atrophy in response, in many cases permanently.

There are ways to "hack it".

For example, ~6 months ago I started trt (testosterone replacement). It was the best decision health wise ever. I feel way better psychologically, first time in my life I managed to stick with cardio training for so long (before 3 months was the most). There are other benefits too.

So what about the "loose it" part? Well there is a hormone called HCG one can take a twice a week to trick one's balls into producing some natural testosterone. Its use prevents atrophy and infertility.