GHK Cu is the compound your body made at 25 and quietly stopped making. Most people find it in overpriced serums. Few understand what it actually does, or what happens when you're not GHK Cu as a multifunctional copper peptide: synthesis routes, process engineering and emerging applications Systems Microbiology and Biomanufacturing Springer Nature Link Constitutive ghrelin receptor activity enables reversal of dopamine D2 receptor signaling: Molecular Cell Peptides for Longevity: BPC 157, TB 500, GHK Cu & CJC 1295