GHK Peptide Injection and GHK Cu Benefits, Uses ,safety GHK Cu vs AHK Cu: Which Copper Peptide Is More Effective? Four reasons this serum belongs in your routine. GHK Cu Peptides that firm and support collagen renewal. Barrier support to keep your skin healthy and resilient. No injection. No needles. No clinic visit. GHK Cu vs AHK Cu: Which Copper Peptide Is More Effective? GHK CU Beverly Hills Rejuvenation Center