What are the differences between topical and intravenous (IV) administration of Glycyl Histidyl Lysine Copper (GHK Cu) for skin health and wound healing in patients? Middle aged mice treated with GHK Cu peptide administered intraperitoneally or intranasally show behavioral rescue but divergent hippocampal aging programs bioRxiv Before vs. after 3 months of GHK Cu peptide therapy smoother texture, more even tone, and skin that looks healthier overall. Small peptide, big difference 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