Copper Peptide Serum for Hair Regrowth & Thinning Hair Feline Skinscience Say hello to your skin's new BFF GHK Cu is a powerful peptide that supports collagen production, speeds healing, improves hair growth, and helps fight visible signs of aging. This tiny molecule Small molecules. Powerful results. Experience Peptide Power with Hairgenetix's advanced Copper Peptide Hair Growth Serum, formulated with 10% GHK Cu and 5% AHK Cu to support hair health at the follicle level. Helps GHK Cu Dosage Calculator GHK Cu Copper Peptide Reconstitution