Not all copper peptide serums are formulated the same Before you buy one, make sure you're actually getting pure GHK Cu at the right concentration not just a diluted blend. We spent Copper Peptide Hair Growth Serum AHK Cu & GHK Cu + Licorice Peptide Labz Seattle GHK Cu Peptide for Skin and Aesthetics Juvasonic + Vitali Copper Peptide (GHK Cu) Bundle Amazon.com: Skin Perfection Copper Peptide Serum GHK CU 1% for Face & Hair Copper Peptides for Skin, Hair, & Scalp 1% Blue Liquid for Face, Neck, Body, Scalp Multi Use Serum Booster with