You started using a GHK Cu peptide serum on your face and now , The things no one tells you., Yes, the injections can hurt like a bitch. , Heres the thing Ive found it works even better topically, GHK CU Peptide: The Next Frontier in Age Management AWP Ever heard of GHK Cu peptide? It's a naturally occurring copper peptide that helps repair tissue, stimulate collagen, and support skin healing. When used in injectable form, it works at a deeper level Peptide Injection Site Reactions: What's Normal, What's Not, and What Revolution Health & Wellness