Your copper peptide product should be this exact blue. If it isn't, you already have your answer. GHK Cu is blue because of coordination chemistry, not dye. The Cu ion at the center Copper Tripeptide Ghk Cu AHUALYN GHK Cu is getting a lot of attention right now, and for good reason. This is not just a skin peptide. It's a copper binding tripeptide with documented effects on gene expression, collagen synthesis, The GHK Cu delays aging in Caenorhabditis elegans via coordinated regulation of mitochondrial function and activation of DAF 16 SKN 1 pathways Biogerontology Springer Nature Link The GHK Cu delays aging in Caenorhabditis elegans via coordinated regulation of mitochondrial function and activation of DAF 16 SKN 1 pathways Biogerontology Springer Nature Link