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 Amazon.com: Skin Perfection GHK Cu Copper Peptide Powder 99.7% Pure DIY Copper Peptides Serum for Face and Scalp Cosmetic Grade GHK Cu 1 Gram Creates Up to 100ml for Fuller Hair and GHK Cu Peptides for Research 99% Purity Guaranteed GHK Cu 50mg Particle Peptides