The Effect of the Human Peptide GHK on Gene Expression Relevant to Nervous System Function and Cognitive Decline 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 Tachyphylaxis an overview ScienceDirect Topics Tachyphylaxis and Tolerance: Biomathematics of Rate Sensitivity biomathematicsblog TOLERANCE & TACHYPHYLAXIS