GHK Cu Copper Peptide Hair Tonic for Fuller Looking Hair 12 Week Supply (30 mL) 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 El GHK Cu (Copper Peptide) for Hair Supports healthier, stronger looking hair Helps nourish the scalp and hair follicles Promotes thicker, fuller appearance Encourages improved Hair Growth Serum Intense with Copper Peptide GHK Cu