Master Immunomodulatory Neuropeptide & Circadian Rhythm Regulator
VIP — Vasoactive Intestinal Peptide
VIP (Vasoactive Intestinal Peptide) is a 28-amino-acid neuropeptide that acts as a master anti-inflammatory signal throughout the nervous system, gut, and immune system. An inhaled form (Aviptadil) is FDA-approved for pulmonary hypertension.
VIP binds VPAC receptors on immune cells, suppressing the NF-kB inflammatory cascade and blocking production of TNF-alpha, IL-6, and other pro-inflammatory cytokines. It also promotes regulatory T-cells and regulates circadian rhythms.
Chronic inflammation drives autoimmune disease, cardiovascular disease, and neurodegeneration. VIP suppresses the NF-kB pathway while promoting immune tolerance — a uniquely powerful combination for inflammation research.
VIP is a pleiotropic neuropeptide with FDA approval (inhaled), Phase II/III clinical trial data for ARDS and COVID-19, and a well-characterized mechanism for suppressing chronic inflammation.
VIP (Vasoactive Intestinal Peptide) is a 28-amino-acid neuropeptide produced throughout the nervous system, gut, and immune cells. It exerts potent anti-inflammatory effects by suppressing pro-inflammatory cytokines (TNF-alpha, IL-6, IL-12) and promoting regulatory T-cell differentiation. An inhaled form (Aviptadil) is FDA-approved for pulmonary hypertension.
VIP is a 28-amino-acid neuropeptide (3,326.8 Da) belonging to the secretin/glucagon superfamily. It is produced by neurons in the enteric nervous system, hypothalamus, and throughout the peripheral nervous system, as well as by immune cells including T-cells and mast cells.
VIP suppresses chronic inflammation by activating VPAC receptors that inhibit NF-kB signaling, simultaneously promoting regulatory T-cell differentiation and vasodilation.
VIP binds VPAC1 and VPAC2 G-protein coupled receptors, activating adenylyl cyclase and elevating intracellular cAMP. This activates PKA, which phosphorylates and inhibits NF-kB — the master transcription factor for pro-inflammatory cytokine production. VIP also promotes Foxp3+ regulatory T-cell differentiation and tolerogenic dendritic cell polarization.
Binds VPAC1 and VPAC2 G-protein coupled receptors, activating adenylyl cyclase and elevating intracellular cAMP — the primary mechanism for its anti-inflammatory and immunomodulatory effects.
Inhibits NF-kB activation in macrophages and dendritic cells, suppressing TNF-alpha, IL-6, IL-12, and IFN-gamma production.
Promotes the differentiation of Foxp3+ regulatory T-cells (Tregs) and tolerogenic dendritic cells, shifting immune responses toward tolerance.
Peer-reviewed literature supporting the research profile of VIP
The following peer-reviewed studies form the primary evidence base for VIP's research profile. All references are sourced from PubMed, NCBI, and peer-reviewed scientific journals. Published research is available through PubMed, NCBI, and peer-reviewed biomedical journals.
Delgado M, Ganea D. Anti-inflammatory neuropeptides: a new class of endogenous immunoregulatory agents. Brain, Behavior, and Immunity. 2008.PMID: 18598752
Comprehensive review of VIP's immunomodulatory functions across innate and adaptive immune compartments.
Delgado M, Pozo D, Ganea D. The significance of vasoactive intestinal peptide in immunomodulation. Pharmacological Reviews. 2004.PMID: 15169929
VIP inhibits pro-inflammatory mediator production through VPAC receptor signaling, supporting its role in immune regulation.
Gonzalez-Rey E, et al. Vasoactive intestinal peptide generates human tolerogenic dendritic cells that induce CD4 and CD8 regulatory T cells. Blood. 2006.PMID: 16397128
VIP induces tolerogenic dendritic cells and regulatory T cells, supporting anti-inflammatory research applications.
Gonzalez-Rey E, Chorny A, Delgado M. Regulation of immune tolerance by anti-inflammatory neuropeptides. Nature Reviews Immunology. 2007.PMID: 17186031
Comprehensive review of VIP's role in immune regulation, neuroprotection, and inflammatory signaling.
Immune Research
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Human data exist for the pharmaceutical form (aviptadil) — its effects are the predictable results of a potent vasodilator
VIP is an endogenous 28-amino-acid neuropeptide with strong vasodilatory, bronchodilatory and immunomodulatory actions. A pharmaceutical form, aviptadil, has been used in combination with phentolamine for erectile dysfunction in some countries and was studied by intravenous infusion in COVID-19 respiratory failure. The adverse-effect profile follows the pharmacology: it lowers blood pressure and raises heart rate.
Research-use information only. Research-grade VIP is not an approved medicine; where trial or label figures appear below they belong to the pharmaceutical product studied, not to any research vial. This section does not give dosing or medical advice.
Every rate carries its source. Where no source exists, no rate is printed.
| Effect | Rate (sourced) | Detail | Source |
|---|---|---|---|
| Hypotension, flushing, tachycardia | not quantified | Direct consequences of VIP-receptor-mediated vasodilation; reported with intravenous aviptadil and expected with systemic exposure. | Delgado et al. 2004 (review of VIP pharmacology) |
| Diarrhoea | not quantified | VIP stimulates intestinal secretion — the mechanism of the diarrhoea seen with VIP-secreting tumours (VIPoma). | Delgado et al. 2004 |
| Injection-site reactions | not quantified | Expected for any injected peptide; unquantified. | General |
Regulatory status: Aviptadil/phentolamine (Invicorp) is approved for erectile dysfunction in some European countries; VIP is not approved in the US. Research-grade VIP is not the approved product.
Everything above describes VIP the molecule. The risk specific to a research vial is different: it may not contain VIP at the labelled amount, and it may contain what the synthesis left behind. Identity (mass spectrometry), purity (HPLC), measured net content and an endotoxin result are the four lines on a certificate that bear on adverse effects, and only a certificate you can check at the laboratory tells you any of them. This is what we have verified for VIP so far.
7 of the 105 vendors on our scoreboard list VIP with a price we read on the product page (23 Sep 2026–1 Nov 2026). Of those, 7 name their testing laboratory, 7 publish certificates that resolve on the lab's own site, and 7 publish measured milligrams against the label. The full ranking, with every dated price, is on Best VIP Vendors.
| Vendor | Rubric | Lab named | Price read |
|---|---|---|---|
| Peptide Giantspartner | 10/10 | Janoshik Analytical · Vanguard Laboratory | $49.99 · 10mg · 1 Nov 2026 |
| Purgo Labspartner | 10/10 | SteriGenix · Freedom Diagnostics | $59.99 · 10mg · 1 Nov 2026 |
| Pure Peptides | 9/10 | Kovera Labs | $54.00 · 5mg · 10 Oct 2026 |
| Nexaph | 8/10 | Janoshik Analytical | $33.80 · 10mg · 26 Oct 2026 |
| PS Peptidespartner | 8/10 | North American Diagnostics | $74.99 · 5mg · 23 Sep 2026 |
Top 5 by rubric score; 2 more on the ranking page.
None yet for VIP specifically. The COA library holds the certificates we have read for each vendor on other compounds, which is the next best signal of how that vendor documents a lot.
Mostly what a strong vasodilator does: a drop in blood pressure, flushing and a faster heart rate, plus loose stools because VIP drives intestinal secretion. Those are pharmacology, seen with the aviptadil product; there are no rates for subcutaneous research-grade VIP.
Side-effect section last reviewed 2026-09-13. Moved from the standalone side-effects page on 10 October 2026; text unchanged.
VIP (Vasoactive Intestinal Peptide) is legal to purchase and possess in the United States as a research chemical. It is not a controlled substance under the DEA Controlled Substances Act, and it is not FDA-approved for human use.
| Jurisdiction | Status as stated |
|---|---|
| United States | Not a controlled substance. Legal to purchase as a research chemical. Not FDA-approved for human use. |
| Canada | Not a scheduled substance. Legal for research purposes. Not approved by Health Canada for human use. |
| United Kingdom | Not a controlled drug under the Misuse of Drugs Act. Legal for research purposes. |
| Australia | Not listed as a scheduled substance by the TGA. Legal for research purposes. |
| European Union | Not a controlled substance in most EU member states. Legal for research purposes. |
| WADA / Sports | VIP is not listed on the WADA Prohibited List. Athletes should consult their governing body before use. |
Statements above are as our legal-status page for VIP stated them in 2025; they were moved here on 10 October 2026 and were not re-verified in the move. Regulations change. This is general information, not legal advice; check the current position with your own jurisdiction's regulator before relying on it.
No. VIP (Vasoactive Intestinal Peptide) is not listed as a controlled substance under the US DEA Controlled Substances Act. It is not scheduled at the federal level in the United States.
Yes. VIP can be legally purchased as a research chemical in the United States. It should not be sold or purchased for human consumption.
No. VIP is not FDA-approved for human use as a standalone peptide. It is studied as a research chemical for immune modulation and anti-inflammatory research.
VIP is not listed on the WADA Prohibited List. Athletes subject to anti-doping rules should consult their governing body before use.
VIP is not a controlled substance in most EU member states. It is legal for research purposes, though individual country regulations may vary.
VIP (Aviptadil) has a real clinical research history including Phase 2/3 trials for ARDS and COVID-19. Results have been mixed — some positive signals in small studies but larger trials have not consistently confirmed efficacy. VIP is not approved for any marketed indication.
Purgo Labs offers VIP with ≥99% purity, third-party certificates of analysis, and fast FedEx shipping. This is an affiliate link — we may earn a commission at no cost to you.
