VIP

Assumed mechanism (well-characterized for the endogenous peptide, but efficacy for the marketed uses is not established): VIP binds the G-protein-coupled receptors VPAC1 and VPAC2, raising intracellular cAMP. This drives smooth-muscle relaxation and vasodilation (including pulmonary and systemic vessels) and shifts immune cells toward an anti-inflammatory profile, lowering pro-inflammatory cytokines (TNF-alpha, IL-6) and modulating regulatory T cells. In CIRS theory it is claimed to re-regulate a dysfunctional innate-immune/neuroendocrine axis (TGF-beta1, MMP-9, C4a, VEGF, MSH), but that downstream clinical claim is theoretical, not proven.

Grades follow the use. COVID-19 respiratory failure has several randomized trials, so those claims count toward A even though the main results were negative; the result shows as its own tag. The nasal-spray CIRS use has no randomized trial and is graded C.

Adverse events

VIP is a potent vasodilator, so the consistent acute adverse effects are dose-dependent hypotension (sometimes with compensatory tachycardia), facial flushing/warmth, headache, dizziness, and GI effects (nausea, cramping, diarrhea). Intranasal use commonly causes nasal irritation and rhinorrhea. In the IV COVID and sarcoidosis trials these were generally mild and transient, and no drug-related SERIOUS adverse events were reported, a genuinely reassuring signal for short-course supervised IV use.

Contraindications

Avoid or use only under close supervision in anyone with low baseline blood pressure, hemodynamic instability, hypovolemia, or significant cardiovascular disease, and be cautious with antihypertensives, nitrates, PDE5 inhibitors, or other vasodilators (additive hypotension). The IV form is an ICU/monitored drug for a reason. Pregnancy, breastfeeding, active malignancy, and pediatric use are uncharacterized for the wellness/intranasal context and should be treated as contraindications absent a prescriber's judgment.

Theoretical concerns

Mechanistically, broad VPAC-receptor agonism affects vasculature, immune signaling, secretion and smooth muscle well beyond any single target tissue. The blood-pressure-lowering effect is the main acute hazard (caution with hypotension, hypovolemia, or concurrent vasodilators/antihypertensives). VIP also has growth/proliferative and pro-secretory signaling roles, so chronic unsupervised dosing in people with hormone-sensitive or proliferative conditions is a theoretical concern. Because the gut-hormone VIPoma tumor causes severe secretory diarrhea via VIP excess, very high or sustained exogenous exposure is biologically non-trivial.

What nobody knows yet

The single biggest unknown is long-term safety of repeated intranasal/subcutaneous self-dosing over months, there is no controlled dataset for the CIRS/anti-aging pattern of use, only one clinic's open-label follow-up claiming durability. Product identity and purity from gray-market sources is unverified (real content, endotoxin, correct sequence). Whether nasal-delivered VIP reaches the brain or systemic targets at claimed doses, and whether the reported MRI/biomarker changes replicate independently, are open. Drug-interaction and chronic-use data outside short supervised IV courses are essentially absent.

What else could explain the result

In CIRS/mold protocols VIP is deliberately the LAST step, taken only after binders (cholestyramine/welchol), MARCoNS nasal antibiotic eradication, antifungals, correction of MSH/ADH and removal from the moldy environment. That means almost everything a user attributes to VIP is layered on top of months of other interventions plus environmental remediation, making clean attribution nearly impossible. Wellness users also frequently stack VIP with BPC-157, thymosin/TA1, NAD+, methylation support, and lifestyle changes. The strong subjective, energy/cognition-based nature of the reported benefits compounds this.

Is the vial what it says?

Cross-checked the PubMed-indexed Critical Care Medicine RCT (PMID 36044317, primary endpoint NOT significant, OR 1.6, CI 0.86-3.11) and the Lancet Respiratory Medicine TESICO RCT (negative) directly; confirmed FDA twice declined EUA and there is no FDA approval; confirmed half-life via the 1978 human PK study; confirmed the CIRS evidence is small open-label single-network work. Discounted vendor/affiliate peptide sites (peptide catalogs, clinic marketing pages), which uniformly overstate efficacy and omit the negative Phase 3 results.

Half-life and storage

Half-life: Very short, roughly 1 to 2 minutes in plasma, cleared by rapid enzymatic degradation (and shortened further in inflammatory states by complement and protease activity) plus renal clearance. This extremely brief half-life is why the IV drug required continuous/repeated infusion and why intranasal or sustained-release approaches are pursued; it also undercuts simple assumptions about how long any systemic effect lasts.

Once mixed: As a peptide, VIP is heat- and protease-sensitive and prone to degradation. Lyophilized product should be stored cold; reconstituted with bacteriostatic or sterile water, kept refrigerated, protected from light, freeze-thaw cycles and agitation avoided. Compounded nasal sprays are similarly perishable and short-dated. Gray-market lyophilized vials carry real risk of degraded or mis-identified peptide, since the molecule does not tolerate poor handling.

What people report

Volume of reports: mixed. Reports exist but contradict each other.

Moderate but niche and concentrated. Online discussion clusters heavily in the mold-illness/CIRS community (where it is the protocol's capstone) and in longevity/peptide forums; it is far less broadly discussed than BPC-157 or GLP-1 peptides. Much of the visible "information" is vendor and clinic marketing rather than independent user reports.

Mixed and polarized. Within the CIRS community some users report meaningful gains in energy, cognition and inflammation; others report little change, intolerance (headache, BP drops, nasal irritation), high cost, or symptom return after stopping. Because it is always given last in a long protocol, even enthusiastic reports rarely isolate VIP itself.

Low to moderate. The most favorable claims trace back to a single clinical ecosystem (Shoemaker/SurvivingMold) and to vendors selling the product, both of which have incentives. Independent, skeptical, hard-outcome reports are sparse. The credible human evidence that does exist (the IV RCTs) is largely negative and is about a different route and indication than what consumers buy.

• Anecdote, not proof: within the mold-illness/CIRS community, a subset describe a noticeable lift in energy, mental clarity and reduced 'inflamed' feeling once VIP nasal spray is added as the final protocol step, but typically after months of binders and remediation, so attribution is muddy.
• Anecdote: many users report the vasodilatory effects directly, flushing, warmth, lightheadedness or a blood-pressure dip, headache, and nasal irritation/runny nose, especially on early doses; some find this limits how much they can use.
• Anecdote: a recurring theme is cost and access frustration (prescription compounding, short shelf life) and reports that benefits fade after stopping, fueling debate over whether it is 'replacement' or just transient.
• Anecdote: outside CIRS, longevity/peptide users tend to report it as subtle or unremarkable compared with the hype, and more skeptical voices note the failed COVID and pulmonary-hypertension trials when pushing back on marketing claims.

Reports are anecdote, not proof.

Can you tell if it is working?

First documented human use: Human pharmacokinetic and physiologic studies of infused VIP date to the late 1970s (e.g., a 1978 study of VIP in man characterizing its metabolic and circulatory effects). The synthetic form aviptadil entered formal FDA-authorized human trials beginning ~2001. So unlike most gray-market peptides, controlled human trials HAVE been completed, but the largest and most rigorous ones (COVID-19 respiratory failure) were negative on their primary endpoints. No controlled human trial supports the popular intranasal CIRS/anti-aging use specifically beyond small open-label cohorts.

1. 1970VIP isolated from porcine small intestine (Said & Mutt); a 28-amino-acid peptide of the secretin/glucagon superfamily.
2. 1978Pharmacokinetic/physiologic studies of infused VIP in humans characterize its very short plasma half-life and circulatory effects.
3. ~2001Synthetic VIP (aviptadil) granted FDA authorization for human trials; later studied in pulmonary hypertension and sarcoidosis.
4. ~2008-2010Inhaled VIP studies in pulmonary hypertension (single-dose, modest effect) and open-label sarcoidosis (biomarker signal).
5. 2013Shoemaker open-label case series popularizes intranasal VIP (50 mcg/spray) as the final step of the CIRS / water-damaged-building protocol.
6. 2020-2021Aviptadil (RLF-100/ZYESAMI) fast-tracked for COVID-19 respiratory failure; sponsor reports a met primary endpoint in one Phase 2b/3 readout amid controversy.
7. Nov 2021 & July 2022FDA declines Emergency Use Authorization for ZYESAMI in critical COVID-19 (twice).
8. Sept 2023NIH TESICO/ACTIV-3b RCT published in Lancet Respiratory Medicine: no benefit of IV aviptadil, the definitive negative result.
9. 2026VIP sits in Category 1 (substances under evaluation) of FDA's 503A interim list, updated May 2026. It was not among the seven peptides the PCAC heard on July 23-24, 2026, nor among the five FDA lists for its next meeting before the end of February 2027.

• IV aviptadil critical COVID-19 RCT. Critical Care Medicine (PMID 36044317)(196-pt randomized double-blind trial; PRIMARY ENDPOINT NOT significant (OR 1.6, 95% CI 0.86-3.11); secondary survival signal; sponsor-affiliated.)
• Brown et al. 2023, TESICO / ACTIV-3b aviptadil RCT (Lancet Respir Med; PMID 37348524)(NIH multicenter placebo-controlled RCT, Lancet Respiratory Medicine 2023; found NO benefit of IV aviptadil, the definitive negative result.)
• Leuchte et al. 2008, inhaled VIP in pulmonary hypertension (Eur Respir J; PMID 18978135)(Single 100 mcg inhaled dose in 20 patients; small, short-lived pulmonary vasodilation. No longer randomized trial found.)
• Prasse et al. 2010, inhaled VIP in sarcoidosis (Am J Respir Crit Care Med; PMID 20442436)(Open-label 20-pt pilot; safe, reduced TNF-alpha in BAL; biomarker only, no clinical outcome.)
• Dooley et al. 2024, CIRS review of treatment evidence (Ann Med Surg; PMID 39649915)(Review of the CIRS literature. The popular intranasal use rests on small (~20-pt) open-label, uncontrolled, single-network case series, not independently replicated; the key Shoemaker series is not PubMed-indexed, so this review is a stand-in, not independent confirmation.)
• FDA: 503A categories list (Category 1, substances under evaluation), updated May 14, 2026(Lists Vasoactive Intestinal Peptide in Category 1; no route restriction is listed. Not inclusion on the bulks list.)
• VIP human pharmacokinetics in man, 1978 (PubMed)(Early human PK; documents the ~1-minute plasma half-life and circulatory effects.)
• FDA / DailyMed search, aviptadil(Confirms no FDA-approved aviptadil label; FDA declined EUA for ZYESAMI twice (2021, 2022).)
• ClinicalTrials.gov, aviptadil studies(Trial registry across COVID-19 (incl. TESICO/ACTIV-3b) and other indications; useful to see what was tested and how it ended.)
• All Wales Therapeutics and Toxicology Centre (AWMSG) Secretariat Assessment Report 3435, aviptadil/phentolamine mesilate (Invicorp) 25 micrograms/2 mg solution for injection, May 2017, citing the Invicorp SmPC (Evolan Pharma AB, Apr 2015)(dose table)
• Shoemaker RC, House D, Ryan JC. Vasoactive intestinal polypeptide (VIP) corrects chronic inflammatory response syndrome (CIRS) acquired following exposure to water-damaged buildings. Health 2013;5(3):396-401(dose table)
• Leuchte HH et al. Inhalation of vasoactive intestinal peptide in pulmonary hypertension. Eur Respir J 2008;32(5):1289-94. PMID 18978135(dose table)
• Prasse A et al. Inhaled vasoactive intestinal peptide exerts immunoregulatory effects in sarcoidosis. Am J Respir Crit Care Med 2010;182(4):540-8. PMID 20442436(dose table)
• Youssef JG et al. The use of IV vasoactive intestinal peptide (aviptadil) in patients with critical COVID-19 respiratory failure: results of a 60-day randomized controlled trial. Crit Care Med 2022;50(11):1545-1554. PMID 36044317. Dose from the ClinicalTrials.gov record NCT04311697(dose table)
• Brown SM et al. Intravenous aviptadil and remdesivir for treatment of COVID-19-associated hypoxaemic respiratory failure in the USA (TESICO): a randomised, placebo-controlled trial. Lancet Respir Med 2023;11(9):791-803. PMID 37348524(dose table)
• Esendagli D et al. Inhaled aviptadil is a new hope for recovery of lung damage due to COVID-19. Med Princ Pract 2025;34(2):191-200. PMID 39870064. Dose from the open-access full text, PMC11936437(dose table)
• Huberman Lab, Peptides: The Science, Uses & Safety, with Dr. Abud Bakri, June 1, 2026. Full third-party auto-transcript searched for vasoactive, VIP, aviptadil, CIRS and mold: no mentions(dose table)
• Huberman Lab, Dr. Craig Koniver: Peptide & Hormone Therapies for Health, Performance & Longevity, October 7, 2024. Full third-party transcript searched for vasoactive, VIP and aviptadil: no hits(dose table)
• The Peter Attia Drive, #387, AMA #83: Peptides, evaluating the science, safety, and hype in a rapidly growing field, April 13, 2026(dose table)