Fitish Most people don't know GHK Cu by name. Their face does. It's the peptide your body uses to signal collagen production, repair tissue, Instagram GHK Cu is a naturally occurring tripeptide in human plasma. Levels average 200 ng ml at age 20 and drop to 80 ng ml by age 60 (Pickart et al., 2020). That decline tracks with GHK Cu vs NAD+: Which Longevity Peptide Should You Take or Stack? Ultrasensitive and Label Free Detection of Copper Ions by GHK Modified Asymmetric Nanochannels Analytical Chemistry Intermediate Cu(II) Thiolate Species in the Reduction of Cu(II)GHK by Glutathione: A Handy Chelate for Biological Cu(II) Reduction Inorganic Chemistry The potential of GHK as an anti aging peptide Dou Aging Pathobiology and Therapeutics