Peptide Therapy for Hair Growth: Explore Your Options 9 months of consistency with a protocol that works systemically, not superficially. This has included GHK Cu subcutaneous and topical, collagen, protein and an intentional lifestyle ticking off the essentials of sleep, training, Neurogan Health, GHK Cu Copper Peptide, Hair & Scalp Serum Peptide and Enzyme Therapy Santa Rosa GHK Cu is a small copper bound peptide (glycyl histidyl lysine with a copper ion) found naturally in human tissues and fluids. Its levels decline with age, and it plays a role in tissue repair, regeneration,