Copper Peptide 10% GHK CU, 5% AHK CU with Oligopeptide 1 Hair Treatment Serum When your hair feels stronger, you do too. The Hairgenetix Extra Strength Copper Peptide Serum, formulated with 10% GHK Cu and 5% AHK Cu, supports hair health at the root helping strengthen follicles, Copper Peptide Hair Growth Serum 10% GHK Cu & 5% AHK Cu Hairgenetix GHK Cu Copper Peptide Hair Growth Serum Blackbird Skincare: Custom Skincare & Beauty Manufacturer Tailored Solutions for Every Brand