You got your shit backwards dude, ask any vet in the game, that's been ON gear for 2 years straight, they gotta keep ramping dosages up and cycling compounds in and out because after a few months the products start flatlining.
i know that people do this kind of thing. because they think they have to. but in fact all the science proves that they are incorrect and that its just the opposite. all those things i mention above are fact and are proven by science. cycling compounds is another myth as well.
one thing that might be true is that after a certain point your body will beocme so muscullar that insulin will be very hard to get elevated, and meeting sufficient calorie intake for growth will be very hard, so either you have to up the doseage of AAS, or use exogenous slin. ive also read about satellite cells becomeing TOO dense, at which point they might actually become counterproductive, and thus you would have to run some pegMGF in order to counter balance this.
im not a endocrinologist, i dont know the exact details, but the upregulation in response to hormones is fact and proven.