GHK Cu Copper Peptide Hair Tonic for Fuller Looking Hair 12 Week Supply (30 mL) 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 Peptide Hair Regrowth Formula GHK CU & AHK CU, Copper Peptide Hair Growth Treatment Serum For Men & Women Fruugo NO Copper Peptide Hair Growth Serum AHK Cu & GHK Cu + Licorice Peptide Labz