Glucocorticoids and the regulation of growth hormone secretion Nature Reviews Endocrinology GHK Cu: The Peptide That Supports Healthy Aging GHK Cu (copper peptide) is naturally occurring in the body and plays a role in supporting skin health, collagen production, and tissue repair. As GHK Cu Peptide: What It Does for Body Composition and Metabolic Health Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance[v3] Preprints.org Amazon.com: GHK Cu Copper Peptide Oral Liquid Drops, 6 in 1 Liposomal GHK Cu Supplement w. Marine Collagen Peptides, Hyaluronic Acid, Biotin & Grape Seed, Support Skin Elasticity, Anti Aging, Hair Growth & Nails : Health Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance[v3] Preprints.org