PeptideNeuropeptideAnti-inflammatoryIntranasal

VIP (Vasoactive Intestinal Peptide)

Also known as Aviptadil (IV form) · Vasoactive intestinal polypeptide

Written by enwyReviewed 5 Aug 20261 sources0 comments

VIP is a 28-amino-acid neuropeptide with real physiology (vasodilation, immune modulation) that is used off-label as an intranasal spray, notably in the CIRS/mold-illness community following Shoemaker protocols. Human evidence outside its natural role is limited to small case series and open-label reports.

01 Overview

Vasoactive intestinal peptide is an endogenous signalling molecule that relaxes smooth muscle, stimulates secretion, and exerts anti-inflammatory effects via VPAC receptors. It is well characterised as a hormone, and inhaled VIP (aviptadil) has been studied for pulmonary hypertension and ARDS.\n\nIn the peptide-therapy world VIP is most associated with intranasal use in chronic inflammatory response syndrome (CIRS) protocols, where uncontrolled reports describe symptom and biomarker improvement. Rigorous, blinded human trials for these indications do not exist, so intranasal VIP remains experimental.

02 Mechanism

Binds VPAC1/VPAC2 G-protein-coupled receptors, raising cAMP to produce vasodilation, bronchodilation and downregulation of pro-inflammatory cytokines.

03 Dosing

Tier	Dose	Route	Notes
CIRS protocol	50 mcg	Insufflated	Shoemaker protocol: 50 mcg intranasal up to 4x/day.

04 Effects

Effect	Magnitude	Evidence
Reduced inflammatory markersOpen-label CIRS reports describe improvements in TGF-beta1, C4a and symptoms; not confirmed in controlled trials.	n/a	Anecdotal
Vasodilation / pulmonary effectsIV/inhaled VIP produces measurable pulmonary vasodilation, the basis of aviptadil trials.	n/a	Clinical

05 Side effects

Effect	Severity	Frequency	Evidence	Countermeasures
Diarrhea / GI upsetVIP stimulates intestinal secretion; loose stools are a recognised effect (VIPomas cause watery diarrhea).	Mild	Common	Observational
Hypotension and flushingAs a potent vasodilator VIP can cause flushing, lightheadedness and blood-pressure drops, especially systemically.	Moderate	Dose-related	Clinical

06 Legal status

United States

Compounded prescription

Intranasal VIP is dispensed via compounding pharmacies; not an OTC product. · as of Jan 2026

07 References

Vasoactive intestinal polypeptide: an anti-inflammatory neuropeptideAnn N Y Acad Sci, 2006

08 Discussion0 comments

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This page is reference information, not medical advice. Doses and protocols are documented as they appear in the clinical literature and in practice — describing them is not a recommendation to use them. Countermeasures listed here are not a substitute for a physician. Legal status varies by jurisdiction and changes.