Not too big. Not too small. Because of their intermediate size, macrocyclic peptides combine the potency and precise targeting of an antibody or biologic therapy with the stability and ease of administration of a GHK Cu may Prevent Oxidative Stress in Skin by Regulating Copper and Modifying Expression of Numerous Antioxidant Genes Identification, characterization, and structure activity relationship of the ASIC3 selective peptide WRPRFa Communications Chemistry Biological efficacy of GHK Cu after ionic liquid loading. (a) Cellular Download Scientific Diagram