Selected Biomarkers Revealed Potential Skin Toxicity Caused by Certain Copper Compounds Scientific Reports GHK Peptide as a Natural Modulator of Multiple Cellular Pathways in Skin Regeneration Pickart 2015 BioMed Research International Wiley Online Library Viral claim says GHK Cu reset nearly 4,000 genes to a younger state and increased collagen production in a preclinical study. This refers to research on GHK Cu, a naturally occurring copper binding peptide that GHK Cu as a multifunctional copper peptide: synthesis routes, process engineering and emerging applications Systems Microbiology and Biomanufacturing Springer Nature Link