GHK CU C2 Peptides Blue Copper Ghk cu Peptide Manufacturers Suppliers Factory Salispharm 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 China GHK Cu Powder Manufacturers Suppliers Factory Wholesale GHK Cu Powder in Stock 99% Pure Copper Peptides (ghk cu) Great for DIY 1 Gram Etsy