Compound Profile · Immune / Inflammatory Hub
Vasoactive Intestinal Peptide · VIP-28 · Aviptadil (synthetic form)
A 28-amino-acid neuropeptide the body already makes — in the brain, gut, lung, and immune tissue — that acts as one of the immune system's master "stand down" signals. VIP is not an optimization peptide. It is a targeted tool for chronic inflammatory states that have stopped responding to everything else: mold-driven CIRS, long-COVID neuroinflammation, and complex mast-cell presentations.
Why This Page Exists
Search VIP and you'll find two things: clinics selling it as a mold-illness miracle, and forums full of people who tried it out of order and got worse. Almost nobody explains the one fact that decides whether VIP helps or fails — that it is the final step of a sequenced protocol, not a starting point. This profile grades the evidence honestly, states the regulatory reality plainly, and names exactly who VIP is — and isn't — for.
Regulatory Status
The synthetic recombinant form, Aviptadil, holds FDA orphan-drug status for acute respiratory distress syndrome (ARDS) and pulmonary arterial hypertension, and was studied in COVID-19 respiratory-failure trials with mixed results. VIP is not FDA-approved for CIRS, mold illness, long COVID, optimization, or longevity. Those are investigational uses.
Outside its orphan indications, VIP reaches patients as a physician-compounded intranasal preparation or as a research chemical. Quality, potency, and delivery-device consistency vary widely (see Sourcing & Quality below).
VIP is not explicitly named on the current WADA Prohibited List, but as a peptide hormone with signaling activity it sits in an ambiguous zone. Competitive athletes should verify current WADA status independently before use.
Genuine Aviptadil is prescription-only. VIP is not DEA-scheduled, but that does not make research-chemical sourcing safe or its clinical claims legal — vendors promising to "cure" CIRS or long COVID are violating FTC advertising rules.
Molecular Profile
28-amino-acid neuropeptide; first isolated by Said & Mutt in 1970 from intestinal tissue, later found throughout the nervous, pulmonary, gut, and immune systems.
Two G-protein-coupled receptors: VPAC1 drives immune and inflammation regulation; VPAC2 drives vasodilation and hormone signaling. The dual activity explains both the anti-inflammatory benefit and the blood-pressure caution.
Produced natively in central and peripheral nerves, gut, lung, and immune tissue. VIP is a physiological "resolve inflammation" signal, not a foreign molecule.
Intranasal delivery is preferred because it crosses the blood-brain barrier for central nervous-system access — central to both CIRS and neuroinflammation use. A subcutaneous form exists but is reserved for systemic immune work.
Mechanism of Action
VIP works at the intersection of immune signaling, the brain, and the vasculature. Its defining action is telling the immune system's inflammatory arm to switch off and its regulatory arm to switch on.
The most-studied mechanism. VIP shifts macrophages from the inflammatory M1 phenotype toward the regulatory, tissue-repairing M2 phenotype, suppresses TNF-α, IL-6, IL-12, and IFN-γ, and expands regulatory T cells.
VIP → VPAC1 → ↓ TNF-α · IL-6 · IL-12 · IFN-γ → ↑ M2 macrophages · ↑ TregsCentral to the Shoemaker CIRS model: VIP is hypothesized to help re-regulate disordered antigen presentation after mold-biotoxin exposure or post-infectious inflammatory syndromes — the step that lets a stuck immune response finally reset.
VIP is a potent vasodilator on vascular smooth muscle — the basis for the ARDS and pulmonary-hypertension research, and simultaneously the reason it can drop blood pressure in susceptible people.
VIP → VPAC2 → vascular smooth-muscle relaxation → ↓ pulmonary & systemic vascular resistanceDelivered intranasally, VIP crosses the blood-brain barrier, modulates microglial activation, reduces neuroinflammation, and supports neurogenesis in preclinical models (Delgado 2008; Gonzalez-Rey 2007) — the rationale for long-COVID and brain-fog applications.
VIP reduces mast-cell degranulation, which is why it's discussed as an adjunct in mast cell activation syndrome (MCAS) — though the same population can flare early before stabilizing (see Cautions).
Primary Use Cases
The Decisive Detail
This is the single most important thing to understand about VIP, and the reason most self-directed attempts fail. In the Shoemaker CIRS protocol, VIP is deployed only after the earlier stages are complete:
Evidence Summary
| Source / basis | Type | Key finding |
|---|---|---|
| Said & Mutt, 1970 | Discovery | First isolation of VIP from intestinal tissue; established it as an endogenous neuropeptide with vasoactive and signaling roles. |
| Delgado et al., 2008 · Gonzalez-Rey et al., 2007 | Preclinical | VIP modulates microglial activation, reduces neuroinflammation, and supports neurogenesis in animal models — mechanistic basis for CNS applications. |
| Shoemaker protocol literature | Observational | Intranasal VIP as final CIRS step; clinic-reported improvements in symptom scores, VCS testing, and markers (TGF-β1, C4a, MMP-9). Not FDA-validated. |
| Aviptadil ARDS trials (Relief Therapeutics / NeuroRx) | Phase 2/3 | Inhaled Aviptadil for COVID-19 respiratory failure — mixed results; did not yield full FDA approval for that indication. Orphan-drug status retained for ARDS/PAH. |
| Preclinical autoimmune models | Animal | Benefit shown in colitis, arthritis, and lupus models; not yet translated to controlled human trials. |
Protocols & Timeline
The dosing below reflects the published Shoemaker intranasal approach and integrative-medicine practice. It is not prescribing guidance — VIP protocols require physician oversight, and the compound is fragile and easy to under-deliver.
The standard CIRS route. Many protocols begin once-daily for the first week to assess tolerance, then escalate to four times daily. Compounded into a metered nasal-spray bottle — device quality matters as much as the peptide.
Used only for systemic immune modulation, not the preferred route for CIRS or neurological indications. Never combined with another compound.
Four doses spread morning → evening. No fasting requirement. VIP can be alerting, so the final spray is placed several hours before sleep.
Red Flags & Cautions
Sourcing & Quality
Genuine Aviptadil is orphan-drug, prescription-only. Research-chemical VIP varies significantly in quality — a certificate of analysis is essential.
Intranasal delivery quality matters as much as the peptide. Cheap metered sprayers routinely under-dose or deliver inconsistently.
VIP is fragile and degrades quickly at room temperature once reconstituted. Vendors selling pre-mixed solution without cold-chain shipping should be avoided.
Promises to cure CIRS, long COVID, autism, or autoimmune disease violate FTC rules. VIP is investigational. Suspiciously low bulk pricing signals purity problems.
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