The GHK Cu pen works. But needles at home were never the answer. We took the same clinically backed copper peptide complex and put it into a serum you can use in 30 seconds, BLUE PEPTIDE SPRAY Young Goose 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 : GHK CU Spray 12MG, 30ML Bottle Evolving Nation Young Goose Blue Peptide Spray Mitochondrial Upgrade Mist Have you heard of the peptide GHK Cu?, GHK Cu is one of the most promising peptides for improving skin health. It can promote collagen production, which is essential for skin elasticity and firmness.