Lets talk GHK Cu (Copper Peptides). , What is GHK Cu?, GHK Cu is a naturally occurring copper complex found in our bodies. As we age, our levels of it drop significantly (sad, we know). When GHK Cu Peptide Therapy: The Definitive Clinical Guide to Gene Modulation, Protocols, and Efficacy GHK Cu Copper Peptide Hair Serum 30ml Azur Skin The Effect of the Human Peptide GHK on Gene Expression Relevant to Nervous System Function and Cognitive Decline