Copper Peptide Hair Growth Serum for Hair Loss & Thinning Hair Feline Skinscience 40% Off! Neurogan GHK Cu Copper Peptide Hair & Scalp Serum Mayraki Hair Growth Serum Intense with Copper Peptide GHK Cu Hair Growth Serum for Woman and Man, Hair Growth Oil, Hair Regrowth Treatment, Hair Two Ingredients. Real Hair Transformations. How Neurogan Health's GHK Cu Serum Is Changing What Customers Expect From Hair Care Glow from within GHK Cu is one of the most powerful regenerative peptides for skin, hair, and total tissue health Think: boosted collagen, enhanced healing, and real, visible rejuvenation over time.