Hair Growth Serum Intense with Copper Peptide GHK Cu Mayraki Copper Peptide Hair Growth Serum 10% GHK Cu & 5% AHK Cu Hairgenetix 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 GHK Cu Copper Peptide Shampoo Anti Hair Loss Shampoo Promotes New Peptide Labz GHK Cu for stronger, thicker hair growth