Histamine2 receptor antagonists: Rapid development of tachyphylaxis with repeat dosing 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 Copper Peptide High Quality R&D, Formulation & Manufacturing Expertise Oraltide Pharma Differences between Tolerance and Tachyphylaxis (Desensitization) in Pharmacology