Overview
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In plain language
VIP (vasoactive intestinal peptide) is a natural messenger of 28 amino acids found in the gut, brain and nerves. It relaxes muscles in the gut and blood vessels, and it increases fluid release in the intestines.
Rare tumors that make too much VIP cause severe watery diarrhea. A drug form called aviptadil has been studied for lung conditions, including severe COVID-19, but it is not FDA-approved as a standalone therapy.
For students
VIP was isolated in 1970 by Sami Said and Viktor Mutt from pig intestine. It belongs to the secretin/glucagon family and is closely related to PACAP. It acts through VPAC1 and VPAC2 receptors, raising cAMP.
Its actions include smooth-muscle relaxation, blood vessel widening, intestinal water and chloride secretion and regulation of immune cells. It also helps set circadian rhythms in the brain's master clock.
For researchers and instructors
Pathology. VIPomas cause watery diarrhea, low potassium and low stomach acid (WDHA syndrome); somatostatin analogues control symptoms.
Therapeutics. Aviptadil was studied in COVID-19 respiratory failure; the FDA did not grant emergency authorization. Combined with phentolamine, it is approved for erectile dysfunction in some countries.
Pharmacokinetics. Very short plasma half-life (about 1–2 minutes), a major barrier to therapy.
Status. Not FDA-approved as a standalone therapy.
Molecular identity
- Amino acids
- 28
- Molecular weight
- ~3,325.8 Da
- Formula
- C₁₄₇H₂₃₈N₄₄O₄₂S
- Sequence
- HSDAVFTDNYTRLRKQMAVKKYLNSILN-NH₂
Sequence map
Hydropathy
Kyte–Doolittle score per residue. Positive values are water-repelling.
Origin and history
VIP (vasoactive intestinal peptide) was isolated in 1970 by Sami Said and Viktor Mutt from pig intestine. Said had been looking for substances that widen blood vessels.
VIP explained a puzzling disease described in 1958: rare tumors (VIPomas) that cause massive watery diarrhea by releasing too much VIP. A synthetic form, aviptadil, has been studied for lung conditions.
Key people
- Sami I. SaidDiscovered VIP
- Viktor MuttKarolinska Institute peptide chemist
Timeline
- 1970
VIP isolated
- 1970s
Linked to VIP-secreting tumors
See every peptide on one history timeline.
Human evidence
Synthetic VIP (aviptadil) has been tested in clinical trials, including for respiratory failure, with mixed results.
Registration and enrollment are not proof of benefit; check study results directly.
Explore original publications and distinguish preclinical findings from controlled human evidence.
Safety and regulatory status
See every compound on the regulatory tracker.
Not FDA-approved as a standalone therapy.
This profile is educational and does not provide treatment, dosing or sourcing guidance.
Sources
- PubMed literature search: VIP
- PubChem compound search: VIP
- PubMed: Said Mutt 1970 VIP
- ClinicalTrials.gov search: VIP
Hernandez Gener, E. (2026, November 7). VIP: molecular data, research history and evidence. VALREXA Biosciences. https://valrexa.com/peptides/vip.html
APA style · Last reviewed November 7, 2026 · Our editorial standardsLast reviewed November 7, 2026. Trial and regulatory status can change; confirm in the linked registries. This profile is educational and is not medical advice, a treatment recommendation, or dosing or sourcing guidance. Report an error · Corrections policy