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 Histamine2 receptor antagonists: Rapid development of tachyphylaxis with repeat dosing Expression and Purification of Recombinant GHK Tripeptides Are Able to Protect against Acute Cardiotoxicity from Exposure to Waterborne Copper in Zebrafish TOLERANCE & TACHYPHYLAXIS Expression and Purification of Recombinant GHK Tripeptides Are Able to Protect against Acute Cardiotoxicity from Exposure to Waterborne Copper in Zebrafish New Biotinylated GHK and Related Copper(II) Complex: Antioxidant and Antiglycant Properties In Vitro against Neurodegenerative Disorders