VIP: The Peptide Named After the Wrong Organ
Discovered in the gut, named for what it did to blood vessels, and now studied mostly for immune and neurological work. VIP is a lesson in how early names stick.
What Is VIP?
VIP is a 28-amino-acid neuropeptide, first isolated from intestinal tissue in 1970 and named for its effect of dilating blood vessels. Both halves of the name have aged poorly: it is found throughout the body rather than mainly in the gut, and vasodilation is now a comparatively minor part of why it is studied.
Why the name misleads, in plain language: imagine naming a person after the room you first met them in and the first thing you saw them do. That is roughly how VIP got its name — found in the intestine, observed relaxing blood vessels, labelled accordingly. It has since turned up in the brain, the lungs, and throughout immune tissue, and its most active research area is now inflammation regulation. The name is a permanent record of what a laboratory happened to notice first in 1970, and it is a useful reminder that a compound’s name describes its discovery rather than its importance.
What the Research Examines
VIP acts on receptors present across immune and neural tissue, and research examines its role in regulating inflammatory responses — particularly its apparent capacity to dampen excessive immune activity rather than stimulate it.
It has attracted research interest in autoimmune and inflammatory conditions, in pulmonary contexts, and in circadian biology, since VIP-producing neurons are involved in the brain’s master clock. Most work remains preclinical and the compound holds no regulatory approval, though a related analogue has been examined in clinical settings.
Frequently Asked Questions
Compiled by the Southern Pacific Labs research team. Last updated July 2026.
Published References
- Said SI, Mutt V. “Polypeptide with broad biological activity: isolation from small intestine.” Science (New York, N.Y.), 1970. PubMed
- Delgado M, Ganea D. “Vasoactive intestinal peptide: a neuropeptide with pleiotropic immune functions.” Amino acids, 2013. PubMed
- Gonzalez-Rey E, Delgado M. “Anti-inflammatory neuropeptide receptors: new therapeutic targets for immune disorders?” Trends in pharmacological sciences, 2007. PubMed
- Iwasaki M, Akiba Y, Kaunitz JD. “Recent advances in vasoactive intestinal peptide physiology and pathophysiology: focus on the gastrointestinal system.” F1000Research, 2019. PubMed
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