MINOXIDIL MELATONIN GHK CU TRETINOIN CAFFEINE SCALP FOAM Beauty Refined GHK Cu Copper Peptide Face Tonic (30 mL) Reduces Appearance of Fine Lines Supports Skin Firmness EllieVate Skin review with prescription strength tretinoin 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 GHK Cu: The Peptide That Transforms Skin and Tissue Health Calibrate Hydration Copper Peptides for Skin: What GHK Cu Does and How It Compares to Retinol