GHK Cu as a multifunctional copper peptide: synthesis routes, process engineering and emerging applications Systems Microbiology and Biomanufacturing Springer Nature Link By age 30, your skin produces about 25% less collagen. By 40, that number can reach 40%. This decline affects more than just how your skin looks. It changes how it heals, Five Peptides Every Endurance Athlete Should Understand The Human Tripeptide GHKCu in Prevention of Oxidative Stress and Degenerative Conditions of Aging: Implications for Cognitive Health Pickart 2012 Oxidative Medicine and Cellular Longevity Wiley Online Library GHK Cu vs NAD+: Which Longevity Peptide Should You Take or Stack? Defy GHK Cu (glycyl L histidyl L lysine) is a naturally occurring copper binding peptide found in human plasma. As levels decline with age, so may its support of the biological processes involved in collagen production, skin