GHK CU COPPER LIQUID SPRAY BOTTLE UMBRELLA Labs Copper Peptide Hair Regrowth Formula GHK CU & AHK CU, Copper Peptide Hair Growth Treatment Serum For Men & Women Fruugo NO Buy GHK Cu Nasal Spray from Peptide Works Have you heard of the peptide GHK Cu?, GHK Cu is one of the most promising peptides for improving skin health. It can promote collagen production, which is essential for skin elasticity and firmness.