Ghk Cu Hair Serum Etsy Small molecules. Powerful results. Experience Peptide Power with Hairgenetix's advanced Copper Peptide Hair Growth Serum, formulated with 10% GHK Cu and 5% AHK Cu to support hair health at the follicle level. Helps Copper Peptide Hair Growth Serum 10% GHK Cu & 5% AHK Cu Hairgenetix GHK Cu Copper Peptide Hair Tonic for Fuller Looking Hair 12 Week Supply (30 mL)