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 GHK cu Serum MCCM Medical Cosmetics Ghk cu Peptide Face Serum NEW Cobalt Blue Bottle 2 Oz Etsy Copper Peptide Serum with 1% GHK Cu peptide, Argireline and Matrixyl 3000 Copper Peptide (GHK Cu) 2% Recovery Serum GHK Cu + KPV Repair Serum PeptiClinic $59