Ozark Have you heard of GHK Cu the copper peptide your body is already making? GHK Cu (Glycyl L Histidyl L Lysine Copper) is a naturally occurring tripeptide found in human plasma, saliva, and urine. GHK Cu Copper Peptide Serum L'orav Breaking: more people are starting to explore copper peptides over retinol Not because retinol is bad but because people are beginning to understand how different ingredients actually work. GHK Cu is something your A Dermatologist's Take on the Copper Peptide (GHK Cu) Trend