GHK Cu Peptide: Hair Regrowth for Thinning & Alopecia GHK Cu Copper Peptide for Hair Loss: Results, Mechanism, and What to Expect GHK Cu, commonly known as copper peptides, are found naturally within the human body where they play a vital role in skin repair and maintenance. Copper peptides support optimal skin function by helping GHK Cu Youthful Skin, Healthy Cells, Vibrant You.