Verified July 2026 · Cited to primary sources
VIP (Vasoactive Intestinal Peptide / Aviptadil): Evidence Grade C. Early / foreign human data only.
The honest verdict
A natural peptide that got a very public shot at the big time and largely missed. VIP itself has real physiology and one approved niche use abroad (erectile dysfunction), which keeps it out of the failed-entirely bin. But the aviptadil respiratory story is the important one, and it was tested properly in a phase 3 trial and did not work, and the FDA declined authorization. Grade C, weighted toward the sobering side. If someone is selling you aviptadil for lung health or recovery, the definitive human trial already said no.
VIP (Vasoactive Intestinal Peptide / Aviptadil) at a glance
- Class
- Neuropeptide (28-amino-acid signaling peptide)
- Mechanism
- VIP is a widely distributed neuropeptide that acts through VPAC1 and VPAC2 receptors. It relaxes smooth muscle (blood vessels and airways), has anti-inflammatory and immune-modulating effects, and in the lung it supports surfactant production and protects certain lung cells. Aviptadil is the synthetic form of VIP. Those lung-protective and vasodilatory properties are the rationale behind trialing it in respiratory failure, pulmonary hypertension, and (combined with phentolamine, as Invicorp) erectile dysfunction.
- Also known as
- Vasoactive intestinal peptide, Aviptadil, VIP, Zyesami, RLF-100, Invicorp component
- Research applications
- Acute hypoxemic respiratory failure, including COVID-19 (tested, failed phase 3)
- Pulmonary arterial hypertension
- Erectile dysfunction (as Invicorp, approved abroad)
- Sarcoidosis and inflammatory lung disease
- Acute respiratory distress syndrome
- Forms
- Intravenous infusion (aviptadil, respiratory trials), Inhaled/nebulized (research), Intracavernosal injection (Invicorp, for erectile dysfunction)
- Legal status
- Research-only
- WADA (anti-doping)
- Not on the WADA Prohibited List and not a recognized performance-enhancing substance. It is a signaling neuropeptide, not an anabolic or oxygen-transport agent.
- Evidence grade
- Grade CEarly / foreign human data only
How we grade evidence
Every grade comes from a fixed A to F rubric: human-trial strength, not hype or affiliate status. Last verified July 6, 2026.
What is VIP (Vasoactive Intestinal Peptide / Aviptadil)?
A natural 28-amino-acid neuropeptide with broad signaling roles. Its big FDA push (aviptadil for COVID) failed a phase 3 trial and the FDA declined authorization, so the evidence is a mixed C.
VIP is a widely distributed neuropeptide that acts through VPAC1 and VPAC2 receptors. It relaxes smooth muscle (blood vessels and airways), has anti-inflammatory and immune-modulating effects, and in the lung it supports surfactant production and protects certain lung cells. Aviptadil is the synthetic form of VIP. Those lung-protective and vasodilatory properties are the rationale behind trialing it in respiratory failure, pulmonary hypertension, and (combined with phentolamine, as Invicorp) erectile dysfunction.
How strong is the evidence for VIP (Vasoactive Intestinal Peptide / Aviptadil)?
Genuinely mixed, and the mix lands at C. On the plus side, VIP combined with phentolamine (Invicorp) is an approved erectile-dysfunction drug in parts of Europe, and there is a large body of human physiology behind the peptide. On the minus side, its highest-profile modern program failed: the phase 3 TESICO trial (n=461) of intravenous aviptadil for COVID-19 hypoxemic respiratory failure was clearly NEGATIVE (odds ratio 1.11, p=0.54; no mortality benefit), and the FDA declined Emergency Use Authorization for aviptadil in November 2021 citing insufficient data. So: real approved use for one narrow indication abroad, but the marquee respiratory indication was tested at scale and failed. That honest tension is a C, not the promising story vendors imply.
Primary sources (2)
- TESICO: intravenous aviptadil and remdesivir for COVID-19 hypoxaemic respiratory failure, randomized placebo-controlled trial, n=461 (NEGATIVE primary endpoint) (Lancet Respir Med, 2023)
- FDA declines Emergency Use Authorization for ZYESAMI (aviptadil) for critical COVID-19 with respiratory failure, November 2021
Is VIP (Vasoactive Intestinal Peptide / Aviptadil) legal? (Status July 2026)
No legal supervised US route.
What is VIP (Vasoactive Intestinal Peptide / Aviptadil) used for?
VIP (Vasoactive Intestinal Peptide / Aviptadil) is marketed for the goals below. See how it ranks against other peptides in each, by evidence, not hype.
What does VIP (Vasoactive Intestinal Peptide / Aviptadil) cost, and how do you access it legally?
Typical cost
$50 to $120 per vial (research-grade aviptadil, quantities vary)
The approved Invicorp (VIP plus phentolamine) is a prescription erectile-dysfunction drug abroad, not a US consumer product. Research-grade aviptadil vials are unregulated and of unverified purity, and IV use is not something to attempt outside a clinical setting.
No legal supervised access route right now.
VIP (Vasoactive Intestinal Peptide / Aviptadil) has no compliant US route today. Vials sold "for research use only" are a gray-market fig-leaf, not a legal loophole, so we don't link them. If you pursue VIP (Vasoactive Intestinal Peptide / Aviptadil), do it with a licensed clinician, and re-check its legal status first.
Is VIP (Vasoactive Intestinal Peptide / Aviptadil)safe? Side effects & risks
In the large COVID trials, intravenous aviptadil was studied in hundreds of patients; the main on-treatment effects are dose-limiting drops in blood pressure and diarrhea from its vasodilatory action, which require monitored infusion. As Invicorp it has an established injection-site safety profile abroad. But this is a potent vasoactive peptide: self-administration is genuinely risky because of hypotension, and there is no FDA-approved aviptadil product in the US. Research-grade material has no oversight. Not for casual or unmonitored use.
Medical disclaimer: This page is independent editorial information, not medical advice, and Best Peptide For That is not a medical provider. We do not provide dosing. Talk to a licensed clinician before starting, stopping, or changing any peptide or medication. Full medical disclaimer.
FAQ
VIP (Vasoactive Intestinal Peptide / Aviptadil) FAQ
Is aviptadil FDA-approved?
No. Aviptadil (synthetic VIP, marketed as Zyesami/RLF-100) is not FDA-approved. The FDA declined Emergency Use Authorization for it in COVID-19 in November 2021, and its phase 3 respiratory trial was negative. The VIP-based erectile-dysfunction drug Invicorp is approved in some European countries, not the US.
Did it work for COVID-19?
No. The phase 3 TESICO trial in 461 patients with COVID-19 respiratory failure found intravenous aviptadil did not improve clinical outcomes or survival versus placebo. That was the definitive test of the respiratory hypothesis and it failed.
Is it safe to use on your own?
Not advisable. VIP is a potent vasodilator, so it can cause significant drops in blood pressure and needs monitored administration. There is no approved US product, and research-grade material is unregulated.
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