Why I Use GHK Cu: The Copper Peptide That Talks to Your Cells GHK Cu is not Botox. It does not freeze a single muscle. It works because it works at the matrix level. GHK Cu stimulates collagen and glycosaminoglycan synthesis, modulates the matrix metalloproteinases that govern GHK Cu Troche Strive Pharmacy 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 Injections: What They Are, What They Promise, and the Big Unknowns