A 28-amino-acid neuropeptide with potent immunomodulatory, anti-inflammatory, and vasodilatory activity.
Binds VPAC1 and VPAC2 receptors on immune cells, endothelium, and smooth muscle. Drives strong anti-inflammatory responses: shifts T-helper cells from Th1/Th17 (pro-inflammatory) to Th2/Treg (regulatory), inhibits mast cell degranulation, reduces TNF-α and IL-6, and relaxes smooth muscle causing vasodilation.
VIP is among the most potent endogenous immunosuppressants known. Research interest is particularly high in CIRS, where VIP levels are often profoundly low and intranasal VIP supplementation has shown promising clinical results in small trials.
VIP's role as a master immune regulator intersects neurology, pulmonology, gastroenterology, and immunology — one of the most pleiotropic peptides studied in research today.