GHK Cu: The Copper Peptide That's Rewriting the Rules of Regeneration GHK Cu vs NAD+: Which Longevity Peptide Should You Take or Stack? GHK Cu vs NAD+: Which Longevity Peptide Should You Take or Stack? Viral claim says GHK Cu reset nearly 4,000 genes to a younger state and increased collagen production in a preclinical study. This refers to research on GHK Cu, a naturally occurring copper binding peptide that