GHK CU for Sale Tripeptide 1 3rd Party Tested US Made GHK Cu is a naturally occurring copper binding peptide that plays a major role in tissue repair and remodeling, with a strong focus in research on skin and hair biology. It works by signaling 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 GHK Copper Peptide GHK Cu Tripeptide 1