Yeah he can chime in. I would welcome more knowledge.
My understanding, and its new to me, is that we get 4-6 pulses/day totalling .5-1.5iu/day the majority if which comes when we first fall asleep.
So if we inject twice with our supplemental GH. This will means we wipe out two of our natural pulses. Ideally we won't inject within a few hours before falling asleep so that we don't wipe out our largest natural pulse.
Exogenous GH won't "shut down" our natural production in the way TEST does to our testes.
But I am just parroting the knowledge and experience of others here. And I am open to rebuke.