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 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 PDF) The Effect of the Human Plasma Molecule GHK Cu on Stem Cell Actions and Expression of Relevant Genes GHK Cu Hair & Scalp Serum 2400mg 4% Less Shedding Neurogan Neurogan Health