A 28-amino acid neuropeptide with potent anti-inflammatory, vasodilatory, and neuroprotective effects across multiple organ systems.
Vasoactive Intestinal Peptide (VIP) is a 28-amino acid neuropeptide belonging to the glucagon/secretin superfamily. First isolated from porcine intestine in 1970 by Sami Said, VIP is produced throughout the body — in neurons, immune cells, and endocrine cells — and acts on VPAC1 and VPAC2 receptors found in virtually every organ system.
VIP functions as a potent vasodilator, bronchodilator, anti-inflammatory, immunomodulator, and neuroprotector. It inhibits pro-inflammatory cytokine production, shifts immune responses from Th1 (inflammatory) to Th2 (regulatory), protects neurons from oxidative damage, and promotes smooth muscle relaxation in blood vessels and airways.
The pharmaceutical form aviptadil (RLF-100) received FDA Fast Track designation during COVID-19 for treatment of respiratory failure. VIP is also used in compounding medicine for chronic inflammatory conditions, mold illness (CIRS), and neurological disorders. Dr. Ritchie Shoemaker's CIRS protocol includes VIP as a late-stage intervention.
Clinical trials of aviptadil (IV VIP) in COVID-19 respiratory failure showed improvements in oxygenation and survival in critically ill patients. Phase 2/3 trials demonstrated reduced mortality in ARDS patients. The mechanism involves protection of type II alveolar cells in the lungs.
In CIRS (Chronic Inflammatory Response Syndrome), VIP nasal spray has been used as part of the Shoemaker protocol to reduce inflammatory markers (TGF-β1, VEGF, C4a) after preceding treatments. Studies show VIP normalizes several CIRS biomarkers. VIP's neuroprotective effects have been studied in Parkinson's and Alzheimer's models.
📚 Key Reference: PMID: 33543254 (aviptadil COVID-19), PMID: 16574288 (VIP immunomodulation)
IV VIP can cause significant hypotension and tachycardia due to vasodilation — must be administered with blood pressure monitoring. Nasal VIP at low doses is generally well-tolerated. GI effects (diarrhea) can occur due to intestinal secretory effects. Contraindicated in active hypotension. Consult your provider.
NOT FDA-approved for routine use. Aviptadil (RLF-100) has FDA Fast Track and Emergency Use Authorization pathways for respiratory failure. Available through compounding pharmacies for other indications. VIP nasal spray is commonly compounded for CIRS protocols.