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 Growth Treatment GHK cu, AHK cu, Licorice Root Extract, Ginseng Root Extact Copper Peptide Hair Growth Serum 10% GHK Cu & 5% AHK Cu Hairgenetix Advanced GHK CU + AHK CU Peptide Hair Growth Serum 30ml Azur Skin Amazon.com : Bloom Clinically Proven Copper GHK CU Peptide Hair Serum for Hair Growth Multi Copper Peptides Non Greasy & Lightweight for Thinning Hair Promotes Fullness, Reduces Shedding Made in USA :