GHK Cu is one of my personal favorites for a lot of reasons, but I can say without a doubt that it's use effectively stopped and reversed, my receiving hairline. However, there are Amazon.com: Copper Peptides GHK Cu Hydra Serum with Hyaluronic Acid Facial Serum for Tightening, Collagen Support, Renewing, Elasticity & Smooth Youthful Looking Skin (30ml 1fl.oz) : Beauty & Personal Care GHK Cu Peptide Therapy: The Definitive Clinical Guide to Gene Modulation, Protocols, and Efficacy If you're using GHK Cu and it stings a little (which is common) this one's for you In this reel I'm sharing the small tweaks that have helped me make peptide injections Copper Peptides for Skin: What GHK Cu Does and How It Compares to Retinol