GHK Cu vs AHK Cu: Which Copper Peptide Is More Effective? Copper Peptide Hair Growth Serum for Hair Loss & 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 Copper peptides (GHK Cu) have been studied for decades for their role in tissue repair and that same biology applies to hair. Research shows GHK Cu may help strengthen existing hair follicles, reduce Copper Peptides for Hair Loss & Regrowth