A GHK Cu face serum appears blue because the active ingredient, GHK Cu (copper peptide), is naturally a blue colored powder, meaning its inherent color transfers to the serum when mixed in; this blue hue Peptide Labz Copper Peptide Hair Growth Serum, 10% GHK cu, 5% AHK cu, Rejuvenates Follicles Walmart.com Mistakes Mixing GHK CU Peptides with Hyaluronic Acid GHK CU 100mg 99%+ Purity, COA Verified Mixed up Ghk cu : r PeptidePathways GHK Cu Peptide Benefits for Skin and Hair LIVV Natural