GHK Cu Peptide: What It Does for Body Composition and Metabolic Health Regenerative properties of the NL GHK Cu peptide and skin appearance Synthagen PL As a skincare founder who has spent $1.3 million testing products and procedures on her own face, I've tried more peptides than I can count at this point. GHK Cu is the one How GHK Peptide Works Signaling GHK acts as a switch for skin repair: Interacts with adenosine receptors reduces inflammation Activates MAPK ERK, PI3K Akt, TGF pathways Stimulates fibroblasts & keratinocytes boosts collagen, elastin