The Power of Blue: Why GHK Cu Is the Unsung Hero of Youth Let's talk about the blue magic no one's talking enough about GHK Cu peptide (that gorgeous blue serum you've L Glutathione Glutathione Supplement Glutathione Reduced 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 Why Is Glutathione Added as a Push? Glutathione IV Power