VIP (vasoactive intestinal peptide)

What Is VIP?

VIP (vasoactive intestinal peptide) is a 28-amino-acid endogenous signalling neuropeptide with vasodilatory, bronchodilatory and immunoregulatory activity. It occurs naturally throughout the nervous, respiratory and gastrointestinal systems, where it acts on VPAC1/VPAC2 receptors. As a therapeutic it is used almost entirely in an inhaled/nasal form and, in some clinical circles, as a compounded intranasal spray for “chronic inflammatory response syndrome” (CIRS) linked to water-damaged-building exposure. The peptide’s biology is well characterised; its use as a CIRS treatment is far less well supported.

Evidence

The best-controlled human data come from respiratory medicine rather than CIRS. An open-label phase II study nebulised VIP in 20 patients with active sarcoidosis for four weeks and reported that it was safe and well tolerated, reduced TNF-α production by bronchoalveolar-lavage cells, and increased CD4+CD25+FoxP3+ regulatory T cells — an immunoregulatory shift in the lung ^{1Reference 1Prasse A et al. · 2010Clinical trialInhaled vasoactive intestinal peptide exerts immunoregulatory effects in sarcoidosis — phase II clinical trialView study →}. Reviews of inhaled VIP agonists frame a broader potential role across asthma, COPD, pulmonary hypertension and sarcoidosis, while noting the peptide’s very short half-life as a practical limitation ^{2Reference 2Wu D et al. · 2013ReviewVasoactive intestinal peptide inhaled agonists: potential role in respiratory therapeutics — review. https://pubmed.ncbi.nlm.nih.gov/23935337/View study →}. The specific claim that intranasal VIP corrects CIRS is widely made in the mould/biotoxin-illness literature but I did not find a citable randomised trial supporting it in this quick pass; treat the CIRS indication as uncited here.

Dosage & Safety

VIP is a peptide drug, not an approved dietary supplement; the intranasal CIRS form is a compounded prescription product, and this entry is informational only. The sarcoidosis study used a nebulised dose over four weeks under clinical supervision ^{1Reference 1Prasse A et al. · 2010Clinical trialInhaled vasoactive intestinal peptide exerts immunoregulatory effects in sarcoidosis — phase II clinical trialView study →}; the intranasal doses used in CIRS protocols are not established by controlled trials and are not given here (they are not a personal recommendation). Because VIP is a potent vasodilator, systemic exposure can in principle cause flushing and blood-pressure changes; formal interaction, pregnancy and long-term-safety profiles for the compounded intranasal form are not established / not assessed in this pass.

References

1. Prasse A, Zissel G, Lützen N, et al. (2010). Inhaled vasoactive intestinal peptide exerts immunoregulatory effects in sarcoidosis — phase II clinical trial. Am J Respir Crit Care Med. https://pubmed.ncbi.nlm.nih.gov/20442436/
2. Wu D, Lee D, Sung YK. (2013). Vasoactive intestinal peptide inhaled agonists: potential role in respiratory therapeutics — review. https://pubmed.ncbi.nlm.nih.gov/23935337/