GHK Cu Topical Cream BLUE Copper Peptide GHK CU Serum with Hyaluronic Acid Anti Wrinkle Assortment eBay Vitali Skincare's 2% vs 3% GHK Cu Skin Cell Restorative Serum GHK Cu What is it and why do you need it? SumaNurica 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