GHK cu is a copper peptide. It's great for skin, especially when you combine it with other things. My favorite is DMSO and derma rolling. My first experience with copper peptides was Procytes How to Mix Ghk Peptide Moisturizer TikTok Amazon.com: Skin Perfection Copper Peptide Serum GHK CU 1% for Face & Hair Copper Peptides for Skin, Hair, & Scalp 1% Blue Liquid for Face, Neck, Body, Scalp Multi Use Serum Booster with Copper Peptide Serum with 1% GHK Cu peptide, Argireline and Matrixyl 3 Dr. Brenner Labs