Any helpful advice--impacts on dosing ghk-cu

I've looked and see dosing for ghk-cu all over the board. I've heard it keeps going down in age but doesn't appear people dose according to age? Or body weight? Just randomly pick between 1and 2.5 mg/day and some cycle off after 8!weeks or so and some don't? Anyone have insight into what goes on in the body, do larger doses actually help or diminishing returns?