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 Copper Peptide Hair Growth Serum 10% GHK Cu & 5% AHK Cu Hairgenetix Copper Peptide Serum with 1% GHK Cu peptide, Argireline and Matrixyl 3 Dr. Brenner Labs A Dermatologist's Take on the Copper Peptide (GHK Cu) Trend