Encyclopedia

VIP

VIP, or vasoactive intestinal peptide, is a 28-amino-acid neuropeptide that binds the VPAC1 and VPAC2 receptors to relax smooth muscle, widen pulmonary vessels, and dampen inflammation. Its synthetic form, aviptadil, has orphan drug designations and human trials in sarcoidosis and ARDS, but no finished product is FDA-approved, and research VIP sells as a compounded or research preparation. Below you'll find reported dosing, safety, and legal status. Educational only, not medical advice.

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Category	Immune
Half-life	1-2 minutes
Regulatory status	Not FDA-approved.

Mechanism

A 28-amino-acid neuropeptide that binds VPAC1/VPAC2 receptors, producing smooth-muscle relaxation, pulmonary vasodilation, and immunomodulatory/anti-inflammatory effects (including reduced pro-inflammatory cytokine production).

Half-life

Very short; endogenous VIP has a plasma half-life of roughly 1-2 minutes, necessitating continuous infusion or inhaled delivery in trials.

Regulatory status

Not FDA-approved. Synthetic VIP (aviptadil) is investigational and has received FDA orphan drug designations (e.g., for sarcoidosis, ARDS) and was studied in COVID-19 ARDS; no approved finished product in the US. Intranasal/research VIP is sold as a research chemical/compounded preparation.

Safety

Reported effects include hypotension, flushing, diarrhea/loose stools, and (rarely) syncope; cardiovascular effects from vasodilation are a key consideration. Human safety data come mainly from controlled trial settings.

Evidence

Multiple human trials (sarcoidosis, ARDS/COVID-19) plus extensive physiology data; efficacy not established for marketed indications.

Sources

Shoemaker RC, House D, Ryan J. Vasoactive intestinal polypeptide (VIP) corrects chronic inflammatory response syndrome (CIRS) acquired following exposure to water-damaged buildings. Health. 2013;5(3):396-401. https://www.scirp.org/journal/paperinformation?paperid=28586
Ryan J, Shoemaker R. RNA-Seq on patients with chronic inflammatory response syndrome (CIRS) treated with vasoactive intestinal polypeptide (VIP). Medical Research Archives. 2016;4(7):1-11. https://esmed.org/MRA/mra/article/view/862
Delgado M, Pozo D, Ganea D. The significance of vasoactive intestinal peptide in immunomodulation. Pharmacological Reviews. 2004;56(2):249-290. https://pubmed.ncbi.nlm.nih.gov/15169929/
Gonzalez-Rey E, Delgado M. Role of vasoactive intestinal peptide in inflammation and autoimmunity. Current Opinion in Investigational Drugs. 2005;6:1116-1123. https://pubmed.ncbi.nlm.nih.gov/16312134/
Petkov V, Mosgoeller W, Ziesche R, et al. Vasoactive intestinal peptide as a new drug for treatment of primary pulmonary hypertension. Journal of Clinical Investigation. 2003;111(9):1339-1346. https://pubmed.ncbi.nlm.nih.gov/12727925/
Gonzalez-Rey E, Fernandez-Martin A, Chorny A, Delgado M. Vasoactive intestinal peptide generates human tolerogenic dendritic cells that induce CD4 and CD8 regulatory T cells. Blood. 2006;107(9):3632-3638. https://pubmed.ncbi.nlm.nih.gov/16397135/

PepWise is an informational and educational tracking tool, not medical advice and not a medical device. VIP may be experimental, restricted, or prescription-only; many research peptides are not FDA-approved. Consult a licensed healthcare provider before starting, changing, or stopping any protocol. Operated by STC Consulting, Inc.