Overview

A real endogenous neuropeptide with legitimate research behind it, and a substantial off-label following in the mould-illness and CIRS communities where the supporting evidence is far weaker than the enthusiasm.

Investigational — not approvedNo approved VIP product in the US. Intranasal preparations are compounded.

At a glance

Regulatory status	Aviptadil (synthetic VIP) was studied in COVID-19 respiratory failure without securing approval. Intranasal VIP is used off-label in chronic inflammatory response syndrome protocols.
Drug class	Endogenous 28-amino-acid neuropeptide
Route	Intranasal (off-label), intravenous or inhaled (trials)
Half-life	~1–2 minutes intravenously
Evidence rating	2/5 Limited Evidence rating 2 out of 5: Limited Preclinical work plus scattered human reports, uncontrolled use, or negative trials.
Studied in	Randomized trials of intravenous and inhaled aviptadil in COVID-19 acute respiratory failure; small studies in sarcoidosis and pulmonary hypertension; no controlled trials of intranasal VIP for CIRS.

How it works

Binds VPAC1 and VPAC2 receptors, producing vasodilation, bronchodilation, pulmonary surfactant production in alveolar type II cells, and broad anti-inflammatory effects including cytokine suppression and regulatory T-cell promotion.

Evidence base

Rated 2 of 5 — Limited. Preclinical work plus scattered human reports, uncontrolled use, or negative trials.

Legitimate mechanism and real trials, but no positive definitive result.

Benefits & potential uses

Bars indicate how well each claim is supported: three = strong human evidence, two = moderate, one = preliminary or preclinical.

Potent anti-inflammatory signalling Moderate evidence

Well-characterised suppression of pro-inflammatory cytokines and promotion of regulatory immune phenotypes.
Pulmonary surfactant and bronchodilation Moderate evidence

Direct effects on alveolar type II cells, the rationale for the respiratory failure trials.
Signals in sarcoidosis Preliminary

Small inhaled studies showed reduced inflammatory markers in bronchoalveolar lavage.
Anecdotal CIRS symptom benefit Preliminary

Reported in uncontrolled clinical series; no randomized data.

Risks, cons & cautions

Bars indicate seriousness: three = serious or common, two = moderate, one = minor.

COVID-19 trials did not secure approval Moderate evidence

Results were mixed and did not persuade regulators, despite emergency-context review.
Hypotension and flushing Moderate evidence

Direct consequence of potent vasodilation; can be significant with intravenous use.
Diarrhea Moderate evidence

VIP is the hormone responsible for the secretory diarrhea of VIPoma; this is on-target, not idiosyncratic.
CIRS use is unvalidated Moderate evidence

The condition itself lacks consensus diagnostic criteria, and the treatment lacks controlled evidence.
Compounded intranasal quality varies Moderate evidence

Formulation and sterility depend entirely on the pharmacy.

Who should avoid it

Hypotension or hemodynamic instability
Pregnancy
Known VIPoma or carcinoid

If used under medical supervision, monitor

Blood pressure
Symptom diaries where used off-label

Regulatory & legal status

No approved VIP product in the US. Intranasal preparations are compounded.

Infographic

Vasoactive Intestinal Peptide (VIP) — benefits & risks at a glance Download SVG

Where to read further

We link to live literature searches rather than a frozen citation list, so you always see current results — including anything published after our last review.

inflammationlungCIRSneuropeptide

Related peptides in Immune & Anti-inflammatory

Terms used on this page

Regulatory T Cell (Treg): Regulatory T cells are a CD4 subset defined by FOXP3 expression that actively suppress other lymphocytes, maintaining tolerance to self and restraining responses once a threat has cleared.
Surfactant Stabilizer (Polysorbate): A surfactant stabiliser is a non-ionic excipient, usually polysorbate 20 or 80, added to occupy interfaces so that the peptide is not the molecule that unfolds at them.
Cytokine: Cytokines are small secreted signalling proteins acting at picomolar concentrations over short distances to coordinate immune cells, characterised by pleiotropy and extensive functional redundancy.
Intravenous Administration (IV): Intravenous administration delivers drug directly into the bloodstream, giving complete bioavailability by definition and making it the reference route against which all others are measured.
Intranasal Delivery: Intranasal delivery uses the nasal mucosa as an absorption surface, offering needle-free administration and rapid onset but low and variable bioavailability for peptides.

This page is educational information, not medical advice. It cannot account for your medical history, medications, or risk factors. Do not start, stop or change any treatment based on it. Speak to a qualified healthcare professional who knows your case.