GHK Cu is the compound your body made at 25 and quietly stopped making. Most people find it in overpriced serums. Few understand what it actually does, or what happens when you're not GHK Cu Peptide Therapy: The Definitive Clinical Guide to Gene Modulation, Protocols, and Efficacy What are the potential side effects and adverse reactions of topical copper peptide? GHK Cu Copper Peptide: The Ultimate Peptide For Longevity The Effect of the Human Peptide GHK on Gene Expression Relevant to Nervous System Function and Cognitive Decline