The Effect of the Human Peptide GHK on Gene Expression Relevant to Nervous System Function and Cognitive Decline Say hello to your skin's new BFF GHK Cu is a powerful peptide that supports collagen production, speeds healing, improves hair growth, and helps fight visible signs of aging. This tiny molecule GHK Cu Peptide: What It Does for Body Composition and Metabolic Health 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.