Copper Peptide Hair Growth Serum for Hair Loss & Thinning Hair Feline Skinscience GHK Cu Copper Peptide: Dosage, Before and After Results, and How It Works Perfect B GHK Cu is one of my personal favorites for a lot of reasons, but I can say without a doubt that it's use effectively stopped and reversed, my receiving hairline. However, there are Copper Peptides for Effective Hair Growth