Andrew Huberman· PhD
In fact, their functions are so closely overlapping on the, you know, when we first look at the face of it that you're probably going to think, why do you have these two systems? So just very briefly, growth hormone-releasing hormone. So remember releasing means it comes from the brain, comes from the brain and tells the pituitary to release growth hormone, and then growth hormone is released into the bloodstream where it goes and acts on a ton of tissues, muscle, ligaments, bone, fat, et cetera, to increase metabolism. It sounds just like thyroid hormone. And they do work in parallel.