GHK Cu Copper Peptide Hair Tonic for Fuller Looking Hair 12 Week Supply (30 mL) Copper Peptide (GHK CU) Serum Australian Private Label Skin Care Cellular Cosmetics What is GHK Cu and Why is Everyone Talking About It? GHK Cu (Copper Peptide) is a powerful, naturally occurring compound in the body that plays a key role in skin health 12 weeks in, and my skin has NEVER looked better! GHK peptides are doing their thing. Alright, I need to give you an updateit's been 12 weeks since I started using GHK