What is VIP used for?

VIP is being researched for pulmonary conditions (pulmonary hypertension, ARDS), inflammatory conditions, and neuroprotection. It is not widely approved for clinical use but has been granted emergency authorizations for specific indications.

Is VIP a natural hormone?

Yes. VIP is naturally produced throughout the body, functioning as both a neurotransmitter and a hormone. It plays roles in vasodilation, immune regulation, and various organ functions.

Why isn't VIP used more widely as a medicine?

VIP's very short half-life (1-2 minutes) and broad biological effects make therapeutic development challenging. Research continues on improved delivery methods and VIP analogues.

Fact-checked by the Peptide Authority Editorial Board · Last reviewed: 1 February 2026

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Immune & Inflammatory•Updated 2026-02-01•5 min read

What Is VIP? Benefits, Research & Safety

A neuropeptide with vasodilatory, anti-inflammatory, and immunomodulatory properties, researched for various therapeutic applications.

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Also known as:

Vasoactive Intestinal Peptide

Vasoactive Intestinal Polypeptide

CLimited human evidenceUK: Sold as 'research only' (UK)WADA: Sport status unclear

UK summary: Endogenous vasoactive peptide. The analogue aviptadil has been investigated for pulmonary indications (including COVID-19 acute respiratory distress) but is not currently a routinely used UK medicine.

Quick Facts

Overview

Vasoactive Intestinal Peptide (VIP) is a 28-amino acid neuropeptide belonging to the secretin-glucagon family. First isolated from porcine intestine in 1970, VIP is now known to be widely distributed throughout the body, functioning as both a neurotransmitter and an endocrine hormone. VIP exerts diverse physiological effects including vasodilation, smooth muscle relaxation, secretion regulation, immunomodulation, and neuroprotection. It plays important roles in the gastrointestinal, cardiovascular, respiratory, and nervous systems. Research has explored VIP's therapeutic potential in numerous conditions including pulmonary hypertension, inflammatory bowel disease, sepsis, and neurodegenerative diseases. Its potent anti-inflammatory and immunomodulatory effects have attracted particular interest. Aviptadil, a synthetic VIP, has been investigated for various conditions. It received FDA Emergency Use Authorization for COVID-19-related respiratory failure in 2020, though results have been mixed. Clinical development continues for pulmonary conditions. VIP's short half-life and broad biological activities present challenges for therapeutic development. Research continues into delivery systems and VIP-based therapeutics with improved pharmacokinetic properties.

Evidence standards summary

VIP — evidence and risk at a glance

Twenty standard modules scored against the Peptide Authority evidence grading methodology. Missing modules indicate the field has not yet been characterised editorially — treat absences as uncertainty rather than reassurance.

01Evidence snapshot

CLimited human evidenceOverall grade against our evidence grading methodology.

Endogenous vasoactive peptide. The analogue aviptadil has been investigated for pulmonary indications (including COVID-19 acute respiratory distress) but is not currently a routinely used UK medicine.

02Human evidence grade

CLimited human evidenceStrength of evidence from published human trials.

03Preclinical evidence grade

BModerate human evidenceAnimal-model and in-vitro evidence quality.

04Regulatory status

UK: Not licensed for general use. May be available in research settings.
EU: Not approved for standard therapeutic use.
Notes: VIP (aviptadil) has been granted Emergency Use Authorization in some jurisdictions for specific indications. It is not widely approved. Clinical trials continue for pulmonary hypertension, ARDS, and other conditions.

05Approved medical uses

None in the UK or EU as a finished medicine. (Or: not yet documented; treat as absence rather than approval.)

06Unapproved / promotional claims

Treats CIRS / chronic inflammatory response syndrome.
Cures 'mould illness'.
Reverses long COVID.

07Common internet claims

Marketed by some private 'functional medicine' clinics for chronic inflammation.

08Claim vs evidence

Claim	Evidence	Human evidence?	Regulatory concern	Safer wording
“Treats chronic inflammation / mould illness”	D	No	High	Mechanistic interest exists for several inflammatory conditions; not a UK-licensed treatment for any wellness-grade indication.

09Safety uncertainty score

Moderate

Safety profile partly characterised; some signals from observational or preclinical data.

10Known adverse signals

Cardiovascular effects (BP, vasodilation).
Injection-site reactions.
Long-term effects of nasal / injectable VIP not characterised.

11Drug-interaction uncertainty

Moderate

Some interaction data published; check with a prescriber for your specific medicines.

12Anti-doping status

WADA: Sport status unclearWADA strict-liability framing applies.

13UK legal position

UK: Sold as 'research only' (UK)

Not licensed for general use. May be available in research settings.

Read the full UK legal guide → Research peptides and UK law

14EU legal position

Not approved for standard therapeutic use.

15What this page cannot tell you

Whether grey-market VIP products contain the labelled compound.
Whether off-label CIRS / long-COVID use produces benefit.

16Last reviewed

Last reviewed: 1 February 2026

Next review due: 1 February 2027

Spotted an error or something out of date? Send a correction.

17Citation quality score

CLimited human evidenceQuality of the sources we cite, graded against the evidence grading methodology.

18Research gaps

No Phase 3 trials for CIRS, mould illness, or long-COVID in the UK regulatory environment.

19Safer alternatives / established care pathways

NHS long-COVID clinic referral via GP.
Specialist immunology assessment for chronic inflammatory concerns.

20Doctor discussion prompts

Questions to ask a qualified clinician

These are starter questions you can adapt for a GP, specialist, pharmacist, or anti-doping advisor. The aim is to help you have a better-informed conversation — not to replace one.

What licensed UK options exist for the inflammatory condition I'm researching?

Discovery & History

VIP was discovered by Sami Said and Viktor Mutt in 1970, isolated from porcine small intestine. It was initially characterised by its potent vasodilatory properties, hence the name "vasoactive intestinal peptide." Early research focused on VIP's gastrointestinal effects, including stimulation of secretion, relaxation of smooth muscle, and regulation of blood flow. Its wide distribution throughout the nervous system was subsequently recognised. In the 1990s and 2000s, research expanded to VIP's immunomodulatory properties. Studies demonstrated potent anti-inflammatory effects and potential in autoimmune disease models. This opened new therapeutic avenues. VIP's role in the lungs became increasingly appreciated, with evidence for vasodilatory and bronchodilatory effects. Research explored VIP for pulmonary hypertension and ARDS (acute respiratory distress syndrome). During the COVID-19 pandemic, aviptadil (synthetic VIP) was rapidly investigated for COVID-19-related respiratory failure, receiving Emergency Use Authorization. While results were mixed, this highlighted ongoing interest in VIP therapeutics. Current research explores improved formulations, delivery systems (such as nasal administration), and VIP analogues with better stability and selectivity.

Mechanism of Action

VIP acts through specific G protein-coupled receptors with diverse downstream effects: **Receptor Activation** VIP binds to two main receptors: - VPAC1: Widely distributed; predominant in immune cells, brain, and liver - VPAC2: Expressed in smooth muscle, gastrointestinal tract, and immune cells - Both couple to Gs proteins, increasing cAMP **Vasodilation** VIP causes potent relaxation of blood vessels: - Increases cAMP in vascular smooth muscle - Stimulates nitric oxide release - Results in vasodilation and reduced blood pressure - Effects in pulmonary and systemic circulation **Anti-Inflammatory and Immunomodulatory Effects** Key therapeutic interest: - Inhibits pro-inflammatory cytokine production (TNF-α, IL-6, etc.) - Promotes regulatory T cell function - Shifts immune responses from Th1/Th17 toward Th2 - Inhibits macrophage and dendritic cell activation **Bronchodilation and Lung Protection** Effects in the respiratory system: - Relaxation of airway smooth muscle - Protection against lung injury - Potential surfactant secretion enhancement - Anti-inflammatory effects in airways **Neuroprotection** CNS effects include: - Protection against excitotoxicity - Anti-apoptotic effects on neurons - Regulation of circadian rhythms - Involvement in memory and learning

Researched Benefits

Based on preclinical and clinical research findings:

1
Potent vasodilation, particularly in pulmonary circulation
2
Anti-inflammatory effects in various models
3
Bronchodilation and airway protection
4
Immunomodulation in autoimmune disease research
5
Neuroprotective properties
6
Potential in ARDS and respiratory failure (under investigation)

Claim vs Evidence

How popular claims about VIP stack up against the current research, graded using our public evidence grading methodology.

Claim	Evidence	Human evidence?	Regulatory concern	Safer wording
“Treats chronic inflammation / mould illness”	D	No	High	Mechanistic interest exists for several inflammatory conditions; not a UK-licensed treatment for any wellness-grade indication.

Theoretical Dosing & Protocols

⚠️ Educational Only: The following information is derived from research literature and is not a prescription or recommendation. No standardised human dosing exists. Always consult a qualified healthcare professional.

Theoretical Dosage	Variable depending on indication and delivery method
Frequency	Variable
Duration	Variable
Notes	VIP/aviptadil is under clinical investigation for various conditions. It is not widely approved for therapeutic use. Short half-life requires consideration of delivery method. Research and clinical use should be under specialist supervision.

Administration Routes

Routes studied in research settings (educational only):

Intravenous (clinical trials)
Inhaled (pulmonary applications)
Intranasal (some research)

Half-Life	Stability
Very short; approximately 1-2 minutes in plasma	Requires careful handling; subject to enzymatic degradation

Safety Profile & Known Risks

Commonly Reported Side Effects

Hypotension (due to vasodilation)
Flushing
Tachycardia
Gastrointestinal effects
Headache

Rare Risks & Concerns

Severe hypotension
Cardiac arrhythmias
Unknown long-term effects

Contraindications

Hypotension
Cardiogenic shock
Certain cardiac conditions
Pregnancy (limited data)

UK & EU Regulatory Context

🇬🇧 United Kingdom

Not licensed for general use. May be available in research settings.

🇪🇺 European Union

Not approved for standard therapeutic use.

VIP (aviptadil) has been granted Emergency Use Authorization in some jurisdictions for specific indications. It is not widely approved. Clinical trials continue for pulmonary hypertension, ARDS, and other conditions.

Clinical Studies Summary

Incidence risk and risk factors for postcholecystectomy syndrome: A systematic review and meta-analysis.

PCS presents a considerable clinical risk, particularly in patients with preexisting symptoms. Clinicians should prioritize preoperative assessment, with special attention to symptomatic patients, and implement individualized perioperative management strategies to mitigate PCS risk.

Medicine (Baltimore). 2026View on PubMed

Risk prediction models for dental caries in children and adolescents: a systematic review and meta-analysis.

Simplified predictive models for childhood caries showed moderate discriminatory performance but exhibited a high risk of bias, as assessed using the Prediction Model Risk of Bias Assessment Tool (PROBAST).

BMJ Open. 2025View on PubMed

Comparative efficacy and safety of biologics and systemic immunomodulatory treatments for chronic urticaria: Systematic review and network meta-analysis.

Among individuals with chronic urticaria refractory to antihistamines, standard-dose omalizumab and remibrutinib are among the most effective drugs across multiple patient-important outcomes with a favorable safety profile across the studied duration. Cyclosporine may be effective but may be among the most harmful.

J Allergy Clin Immunol. 2025View on PubMed

Correlations between social media addiction and anxiety, depression, FoMO, loneliness and self-esteem among students: A systematic review and meta-analysis.

This meta-analysis revealed that SMA was positively associated with anxiety, depression and loneliness but negatively associated with self-esteem. These findings indicate that students with SMA are more likely to suffer from anxiety, depression and loneliness. Conducting larger prospective studies would be beneficial to verify our findings.

PLoS One. 2025View on PubMed

Risk prediction models for deep venous thrombosis in patients with acute stroke: A systematic review and meta-analysis.

Although the included studies reported a certain level of discrimination in the prediction models of DVT in patients with acute stroke, all of them were found to have a high risk of bias according to the PROBAST checklist. Future studies should focus on developing new models with larger samples, rigorous study designs, and multicenter external validation.

Int J Nurs Stud. 2024View on PubMed

Acupressure for depression: A systematic review and meta-analysis.

The pooled results showed that acupressure exhibited a significant beneficial effect on reducing the severity of depression compared with sham acupressure and served as an adjunct to conventional treatment, although the evidence level was moderate. Thus, acupressure may be a potential treatment for depression.

Asian J Psychiatr. 2024View on PubMed

Registered Trials & Regulatory Status

Registered trials

Currently recruiting

Furthest phase

Phase 4

Approved product

Yes

Joette Calabrese Survivalist Kit

21 of 30 completed trials have never posted results. Unreported trials are not neutral: results that go unpublished are more often negative ones.

Video-feedback Intervention to Promote Racial-Ethnic Socialization Competency (VIP-RACE)

Status: Recruiting · 110 participants · Penn State University

Conditions: Depressive Symptoms, Anxiety Symptoms, Conduct Problems

No results postedNCT07055906

Mississippi Violence Injury Prevention (VIP) Program

Status: Not Yet Recruiting · 500 participants · University of Mississippi Medical Center

Conditions: Gun Shot Wound

No results postedNCT06736730

Medical Effects of Proximal (In-person) Intercessory (PIP) and Virtual Intercessory Prayer (VIP) on Pain and Anxiety

Status: Completed · 180 participants · University of Maryland, Baltimore

Conditions: Pain and Anxiety, Complementary Therapies

No results postedNCT07565142

Extraperitoneal SINgle-port rObotic-assisted Radical Prostatectomy (RARP) Versus Transperitoneal Multi-port RARP in the Treatment Of Prostate Cancer (SINO-TOP)

Status: Recruiting · 480 participants · Shanghai Changzheng Hospital

Conditions: Prostate Adenocarcinoma, Localized Prostate Carcinoma

No results postedNCT06238713

Creating VIP Corps to Reduce Maternal Deaths

Status: Recruiting · 2,800 participants · Ann Coker

Conditions: Maternal Morbidity and Mortality

No results postedNCT06089109

Neuropeptide Expression During the Ovarian Cycle and in Patients With PCOS

Status: Unknown · 45 participants · University Of Perugia

Conditions: PCOS

No results postedNCT05958914

Post-market Clinical Investigation of the Angio-Seal™ VIP VCD (ANGIO-SEAL CLOSE)

N/A

Status: Unknown · 230 participants · Terumo Europe N.V.

Conditions: Vascular Closure, Endovascular Procedure, Hemostasis

No results postedNCT05335525

Circumferential Vertebral Reconstruction of Osteoporotic Compression Fractures Using a Novel Bipedicular Peek Implant

Status: Terminated · 23 participants · Icahn School of Medicine at Mount Sinai

Conditions: Vertebral Compression Fractures, Osteoporotic Vertebral Compression Fractures

Results postedNCT05337696

VIP - Vascular Infection Project

N/A

Status: Recruiting · 1,000 participants · University Hospital, Bordeaux

Conditions: Aortitis, Vascular Graft Infection, Blood Vessel Prosthesis

No results postedNCT06866535

Video Interaction Project in Brazil

Status: Completed · 32 participants · NYU Langone Health

Conditions: Parenting

No results postedNCT05198739

A Cardiac Surgery Virtual Nutrition Intervention Program Feasibility Study-VIP Study Protocol

Status: Completed · 20 participants · St. Boniface Hospital

Conditions: Nutritional Deficiency

No results postedNCT05183607

Evaluation of Values in Perspective (VIP) Program

Status: Completed · 850 participants · University of Miami

Conditions: Risk Behavior

No results postedNCT04879342

Adverse event reports (FDA FAERS)

cerebrovascular accident1
device failure1
head injury1
product use in unapproved indication1
syncope1

FDA FAERS spontaneous reports. A report is not proof the substance caused the event, and an absence of reports is not evidence of safety.

Source: ClinicalTrials.gov and openFDA. Updated automatically.

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Frequently Asked Questions

Questions to ask a qualified clinician about VIP