VIP (Vasoactive Intestinal Peptide)
Anti-Inflammatory, Gut Health, Wellness
In short
- A genuine endogenous neuropeptide with wide-ranging roles in vasodilation, immune regulation, and circadian rhythm.
- Its use in this community derives almost entirely from the CIRS/mould-illness protocols associated with Ritchie Shoemaker, which are not accepted by mainstream medicine.
- A VIP analogue (aviptadil) received FDA emergency use consideration for COVID-19 ARDS; the pivotal trial did not demonstrate benefit.
- Extremely short half-life — approximately one minute in plasma.
- Potent vasodilator, so hypotension is the predictable acute effect.
Structure
A 28-amino-acid endogenous neuropeptide. PubChem does not carry a small-molecule entry under this name, and peptides of this size are represented by sequence rather than a structure diagram.
How it works
VIP is a 28-amino-acid peptide of the secretin/glucagon superfamily, acting on VPAC1 and VPAC2 receptors. It is a potent vasodilator, a bronchodilator, an immune modulator with broadly anti-inflammatory effects, and the principal synchronising signal in the suprachiasmatic nucleus.
Its one-minute plasma half-life is the central pharmacological problem: as an endogenous signalling peptide it is designed for rapid local action, not sustained systemic exposure.
Intranasal administration is used in the CIRS protocols on a nose-to-brain rationale that has not been validated for this peptide.
What the research shows
Aviptadil, a synthetic VIP, was studied in COVID-19 respiratory failure. The pivotal trial did not demonstrate the claimed benefit, and the emergency authorisation pathway did not conclude in approval.
Studies in pulmonary arterial hypertension and sarcoidosis have been small.
The CIRS/mould-illness application rests on a diagnostic and treatment framework that mainstream medicine does not recognise, and there are no independent randomised trials supporting it.
Dosing in the literature
Figures below are quoted from published studies, with the species or population they were measured in. They are records of what was studied, not recommendations.
| Studied in | Amount | Route | Source |
|---|---|---|---|
| Human — aviptadil in COVID-19 respiratory failure trials | Intravenous infusion protocols; see trial records | intravenous infusion | PubMed |
| Human — pulmonary hypertension and sarcoidosis studies | Inhaled and infused protocols; small studies | — | PubMed |
Commonly reported ranges
These are amounts people report using. They are not from any study, have not been evaluated for safety, and are reproduced here only because they circulate widely and are better seen alongside the evidence than instead of it.
| Reported by | Amount | Route |
|---|---|---|
| Commonly reported, from CIRS protocols | 50 µg four times daily | intranasal |
No published human pharmacokinetic study establishes a dose, interval, or duration for this compound. Community figures below have no trial behind them and are reports of practice, not evidence. The intranasal protocol comes from the CIRS framework rather than from any pharmacokinetic study. With a one-minute plasma half-life, systemic exposure from any route is brief, and nose-to-brain delivery for this peptide has not been demonstrated.
Handling and storage
Compounded intranasal spray is the route used in the CIRS protocols, typically requiring refrigeration.
Clinical studies used intravenous infusion or inhalation.
VIP is unstable and degrades readily, so handling and cold chain matter substantially.
Side effects
The predictable acute effect is hypotension, because VIP is a potent vasodilator. Flushing, headache, and tachycardia follow from the same mechanism.
Diarrhoea is characteristic — VIP-secreting tumours (VIPomas) cause profound watery diarrhoea, which tells you what sustained systemic VIP elevation does.
Intranasal use reportedly causes local irritation.
Anyone with low blood pressure is in the group where the vasodilatory effect is most consequential.
Combinations
No interaction data. Combining with any vasodilator or antihypertensive compounds the hypotensive effect, which is the most predictable interaction available.
Research status
VIP biology itself is mainstream, important, and well characterised.
Therapeutic development has been limited by the extremely short half-life. The aviptadil COVID programme was the most prominent recent attempt and did not succeed.
The CIRS literature is largely confined to publications by proponents of that framework.
Legal status
Not approved for general use in any jurisdiction. Available through compounding pharmacies by prescription in the US, primarily within CIRS practice. Aviptadil has orphan designations but no general approval.
WADA status
Not specifically named on the Prohibited List. Falls under WADA class S0, which prohibits any pharmacological substance not currently approved by any governmental regulatory health authority for human therapeutic use. Treat it as prohibited in sport.
Conclusion
VIP is real and important endogenous biology whose therapeutic use has repeatedly foundered on a one-minute half-life.
Its presence in this community traces to a diagnostic framework mainstream medicine does not accept, and the strongest recent trial of a VIP analogue was negative. The hypotension is the part that is definitely real.
Sources
Track your own VIP (Vasoactive Intestinal Peptide) protocol
Peppers logs your doses, models your levels from this half-life, tracks your vials and tells you when you will run out. Free on iPhone.
Reference and educational information only. Not medical advice. Nothing here diagnoses, treats, or prescribes, and nothing here is a recommendation to use any compound. The compounds described are research chemicals and are not approved for human consumption. Legal and anti-doping status change — the review date above is when these claims were last checked. Talk to a qualified clinician about anything you intend to take.