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, 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 GHK Cu: The Regenerative Peptide for Skin, Hair, and Healing Pulse & Remedy The Effect of the Human Peptide GHK on Gene Expression Relevant to Nervous System Function and Cognitive Decline The potential of GHK as an anti aging peptide