Cu Peptide Before and After: What to Expect for Skin and Hair GHK Cu is one of the most talked about peptides in aesthetics right now. But how much of what you have heard about it is actually true? Copper peptide, known as GHK Cu, has GHK Cu Copper Peptide: Dosage, Before and After Results, and How It Works Perfect B GHK Cu Copper Peptide Face Tonic (30 mL) Reduces Appearance of Fine Lines Supports Skin Firmness