The potential of GHK as an anti aging peptide Dou Aging Pathobiology and Therapeutics 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 16. Receptor Regulation Principles of Pharmacology Study Guide Expression and Purification of Recombinant GHK Tripeptides Are Able to Protect against Acute Cardiotoxicity from Exposure to Waterborne Copper in Zebrafish