GHK Cu Peptide: Turn Back the Clock Naturally Calibrate Hydration 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 multiple biological processes involved in tissue repair, skin health, and ZenLabs Resources & Tools Why glutathione isn't the antidote Explained though concept chain from Simplify Rx