GHK Cu 50mg vs 100mg: Which Concentration Should You Buy? 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 vs NAD+: Which Longevity Peptide Should You Take or Stack? Cu Peptide Before and After: What to Expect for Skin and Hair What is the difference between ghk cu and ghk cu raw?