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 is one of the most talked about peptides in aesthetics right now. But how much of what you have heard about it is actually true?, Copper peptide, known as GHK Cu, has a growing body of peer GHK Cu vs NAD+: Which Longevity Peptide Should You Take or Stack? Your body made this peptide every day until you turned 30. Then it stopped. GHK Cu (copper peptide) is a naturally occurring tripeptide discovered in 1973. At age 20, your plasma levels sit