VIP Peptide (Vasoactive Intestinal Peptide): Evidence and Status
The short answer
VIP (vasoactive intestinal peptide) is a 28-amino-acid neuropeptide found in the gut, lungs and brain. Its synthetic form, aviptadil, did not significantly improve outcomes in the 2023 TESICO COVID-19 trial and is used with phentolamine as an injection for erectile dysfunction in the UK. Research-grade VIP has no approved use.
"VIP peptide" almost always means vasoactive intestinal peptide, a 28-amino-acid neuropeptide that occurs naturally in the gut, lungs and brain. It is sold by research vendors, and it has a synthetic drug form, aviptadil, with an unusual regulatory history. This page covers what VIP does in the body, what has been tested in people, and what has not. It is a research reference, not medical advice.
What VIP is
Human VIP is a 28-residue peptide with a C-terminal amide, cut from a larger precursor (residues 125 to 152 of UniProt P01282). It was first reported as a vasodilator in 1970, and a 2019 review describes effects on ion secretion, nutrient absorption, gut motility, glycemic control, immune responses and circadian rhythms (F1000Research 2019). It is an abundant neurotransmitter in the lungs as well, with roles discussed in pulmonary hypertension, COPD, asthma, cystic fibrosis and acute lung injury (Life Sciences 2023). The same review names two limits on VIP as a medicine and discusses extended-release formulations and analogues to get around them.
What has been tested in people
| Use | What happened | Source |
|---|---|---|
| COVID-19 respiratory failure (intravenous aviptadil) | TESICO randomised 471 hospitalised adults to aviptadil or placebo between April 2021 and May 2022. Aviptadil did not significantly improve clinical outcomes up to day 90 | Lancet Respir Med 2023 |
| Same use, regulatory side | FDA declined an emergency use authorization for Zyesami (aviptadil) in critical COVID-19 with respiratory failure in November 2021, and declined a second request for a patient subgroup on 1 July 2022 | Pharmafile, NRx release |
| Erectile dysfunction (injection into the penis) | Invicorp combines VIP 25 micrograms with phentolamine 1 or 2 mg for intracavernosal injection; the UK granted a marketing authorisation on 21 April 2015 | BJU Int 2008, AWMSG appraisal 3435 |
VIP nasal spray and "mold illness"
VIP nasal sprays are promoted online for chronic inflammatory response syndrome and related mold-exposure conditions. A PubMed search on 6 November 2026 for vasoactive intestinal peptide with chronic inflammatory response syndrome returned no clinical trial of VIP in that condition, and the aviptadil trials above do not test it. Claims for that use rest on practitioner protocols, not published trials we could find.
Regulatory status
No aviptadil or VIP product is FDA approved: openFDA Drugs@FDA returned no result on 1 November 2026. VIP is not on FDA's list of bulk substances that may present significant safety risks (content current as of 22 April 2026) and is not one of the six peptides in HHS's 30 October 2026 enforcement discretion policy. Research vendors sell it for laboratory use only. See also the legal status guide.
If you handle a research vial: what to check
A certificate of analysis for VIP should show the formula C147H237N43O43S and an average molecular weight near 3326.8 for the full 28-residue amide (PubChem 16132300, aviptadil), with HPLC purity and a mass spec result on the same lot as the vial. A free acid version weighs about 1 more, and a shorter fragment or the related peptide PHM-27, which comes from the same precursor, would not match. Our peptide testing guide explains how to read a certificate, and best place to buy VIP lists the vendors we have reviewed.
Reconstitution calculator for any peptide
Enter the vial strength and the bacteriostatic water you add and get the concentration and the syringe mark for a given amount. It does not tell you what amount to use: no tested dose exists for research-grade VIP.
Open the reconstitution calculator peptulator.com, the Bureau's independent toolFor another peptide researched for its anti-inflammatory profile, see KPV.
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Build your stack, 2 minutesFrequently asked questions
What is VIP peptide?
VIP is vasoactive intestinal peptide, a 28-amino-acid neuropeptide first reported as a vasodilator in 1970. It acts in the gut, lungs, brain and immune system. Its synthetic form is called aviptadil.
Does VIP nasal spray work?
We found no published clinical trial of VIP nasal spray, including for chronic inflammatory response syndrome. The human trials that exist tested intravenous aviptadil in COVID-19 respiratory failure, which did not significantly improve outcomes, and an injection combination for erectile dysfunction.
Is VIP peptide FDA approved?
No. openFDA Drugs@FDA returned no aviptadil or VIP product on 1 November 2026, and FDA declined emergency use authorization for Zyesami (aviptadil) in COVID-19 in November 2021 and again in July 2022. In the UK, Invicorp (aviptadil with phentolamine) is authorised for erectile dysfunction.
What is aviptadil?
Aviptadil is the synthetic form of vasoactive intestinal peptide. It has been studied intravenously in COVID-19 respiratory failure and is part of the intracavernosal combination Invicorp.
Sources (checked 6 November 2026)
- UniProt P01282 (VIP human): vasoactive intestinal peptide residues 125 to 152, asparagine amide end. Checked 6 November 2026.
- Iwasaki et al, Recent advances in vasoactive intestinal peptide physiology and pathophysiology: focus on the gastrointestinal system, F1000Research, 2019. Checked 6 November 2026.
- Zhong et al, The role of vasoactive intestinal peptide in pulmonary diseases, Life Sciences, 2023. Checked 6 November 2026.
- Brown et al, Intravenous aviptadil and remdesivir for treatment of COVID-19-associated hypoxaemic respiratory failure in the USA (TESICO), Lancet Respiratory Medicine, 2023. Checked 6 November 2026.
- Dinsmore and Wyllie, Vasoactive intestinal polypeptide/phentolamine for intracavernosal injection in erectile dysfunction, BJU International, 2008. Checked 6 November 2026.
- All Wales Medicines Strategy Group, appraisal report 3435, aviptadil/phentolamine (Invicorp), UK marketing authorisation 21 April 2015. Checked 6 November 2026.
- Pharmafile, FDA decline emergency use authorisation of Zyesami for patients with critical COVID (5 November 2021). Checked 6 November 2026.
- MarketScreener, NRx Pharmaceuticals announces FDA declines emergency use authorization for Zyesami for subgroup (1 July 2022). Checked 6 November 2026.
- PubChem compound 16132300 (aviptadil): formula, weights, synonyms. Checked 6 November 2026.
- openFDA Drugs@FDA search for aviptadil (no result). Checked 6 November 2026.
- FDA, Certain bulk drug substances for use in compounding that may present significant safety risks (content current as of 22 April 2026). Checked 6 November 2026.
VIP is sold for laboratory research use only, not for human use. Labels and trial records change; the leaflet in your box and your prescriber come first. Educational content, not medical advice.