Ghk cu and skin peptides (topical) Skin regeneration and wrinkle reduction Longevity Protocols Copper Peptides for Skin: What GHK Cu Does and How It Compares to Retinol The Effect of the Human Peptide GHK on Gene Expression Relevant to Nervous System Function and Cognitive Decline GHK Cu as a multifunctional copper peptide: synthesis routes, process engineering and emerging applications Systems Microbiology and Biomanufacturing Springer Nature Link