GHK Cu Copper Peptide: Dosage, Before and After Results, and How It Works Perfect B Essential GHK Cu Serum: What It Is, How It Works, and Why It Matters f Bacteriostaticwater.com 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. The Effect of the Human Peptide GHK on Gene Expression Relevant to Nervous System Function and Cognitive Decline