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 GHK Cu (Copper Peptide): A Smarter Way to Support Skin Regeneration Top Rated Scottsdale Med Spa Babyface 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. Copper Peptide Regenerating Serum for Glowing Skin and Hair