Not all copper peptide serums are formulated the same Before you buy one, make sure you're actually getting pure GHK Cu at the right concentration not just a diluted blend. We spent Copper Peptide Serum with 1% GHK Cu peptide, Argireline and Matrixyl 3 Dr. Brenner Labs Ghk cu Copper Peptide Repair Serum Firming, Collagen Boost, Skin Renewal, Anti aging Face Serum Etsy Copper Peptide 10% GHK CU, 5% AHK CU with Oligopeptide 1 Hair Treatment Serum Copper Peptide GHK Cu Face Serum IWG Copper Peptide Hair Growth Serum 10% GHK Cu & 5% AHK Cu Hairgenetix