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 GHK Cu Peptide for Skin & Hair Facial Serum & Scalp Solution Copper Peptide Serum for Hair Regrowth & Thinning Hair Feline Skinscience Copper Peptide Hair Growth Serum 10% GHK Cu & 5% AHK Cu Hairgenetix Lets talk copper peptides , We get asked this all the time:, Whats the difference between GHK and CP Serum?, Heres your quick guide:, GHK (first generation), Beautiful blue serum, Best for Super CP Serum