PDF) The effect of tripeptide copper complex on human hair growth in vitro GHK Cu (Copper Peptide) has emerged as one of the most promising regenerative peptides for hair restoration due to its ability to stimulate follicular activity, improve scalp circulation, reduce inflammation, and prolong the GHK Cu vs AHK Cu: Which Copper Peptide Is More Effective? Copper Peptide 10% GHK CU, 5% AHK CU with Oligopeptide 1 Hair Treatment Serum eBay