GHK-Cu (glycyl-histidyl-lysine, copper-bound) is a naturally occurring tripeptide found in human plasma, saliva, and urine, with concentrations that decline sharply with age. It has one of the longest research histories of any peptide in dermatological science, largely centered on collagen remodeling and wound-healing signaling.
Mechanism, common research protocols, evidence review, and cited primary literature for GHK-Cu live on the full guide.