GHK Cu is a naturally occurring tripeptide in human plasma. Levels average 200 ng ml at age 20 and drop to 80 ng ml by age 60 (Pickart et al., 2020). That decline tracks with What is the safe topical dosing, duration, and contraindications for the copperbinding peptide GHKCu for wound healing or antiaging? Copper peptides like GHK Cu work by sending signals to your skin to repair, regenerate, and produce collagen. It's not about instant results, it's about improving how your skin functions over time. Dr. PDF) The Effect of the Human Plasma Molecule GHK Cu on Stem Cell Actions and Expression of Relevant Genes