GHK Cu vs NAD+: Which Longevity Peptide Should You Take or Stack? Most people think skincare works at the surface level. But healthy skin function starts much deeper than a temporary glow. GHK Cu is a naturally occurring copper binding tripeptide that is already found Definitive Guide on Peptides for Skin and Hair Care Infusion Clinic ABQ 89030 95 5 GHK Cu Gly His Lys Cu Copper Tripeptide 1; Prezatide copper