GHK Cu Peptide: Hair Regrowth for Thinning & Alopecia Subcutaneous Injection Sites and Instructions for Safe Self Administration 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 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,