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 Glycyl L histidyl L lysine Cu2+ (GHK Cu) Attenuates CuSO4 or LPS induced inflammation in Zebrafish larvae model ScienceDirect Intermediate Cu(II) Thiolate Species in the Reduction of Cu(II)GHK by Glutathione: A Handy Chelate for Biological Cu(II) Reduction Inorganic Chemistry