Amazon.com: Neurogan GHK Cu Copper Peptide Hair & Scalp Serum 2400mg, 4% Copper Peptides Fast Absorbing, Water Based Formula for Hair Softness & Shine Cosmetic Dry Scalp Moisturizer Spray, Made in USA : A few years ago, barely anyone was talking about copper peptides now GHK Cu and AHK Cu are everywhere in skincare, biohacking, and longevity conversations. But did you know there are copper peptides 2% GHK CU Copper Peptide Serum for Hair Growth and Scalp Care Seraphime Copper Peptide Hair Growth Serum 10% GHK Cu & 5% AHK Cu Hairgenetix AHK CU + GHK Cu Hair Serum Pro 4800mg Hair Growth Neurogan