GHK Cu vs AHK Cu: Which Copper Peptide Is More Effective? By age 30, your skin produces about 25% less collagen. By 40, that number can reach 40%. This decline affects more than just how your skin looks. It changes how it heals, 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 The potential of GHK as an anti aging peptide Dou Aging Pathobiology and Therapeutics