VIP
Vasoactive Intestinal Peptide / Aviptadil
Vasoactive Intestinal Peptide (VIP) is a 28-amino acid neuropeptide originally isolated from porcine intestinal tissue that functions as a potent vasodilator, immunomodulator, and neurotransmitter throughout the body. It has gained significant research attention for its potential role in treating Chronic Inflammatory Response Syndrome (CIRS) associated with mold illness, as well as pulmonary arterial hypertension. VIP is typically administered via nasal inhalation in clinical research settings, though injectable forms also exist.
Mechanism of Action
Endogenous 28-amino-acid neuropeptide with broad physiological roles. Potent vasodilator, bronchodilator, and immunomodulator. Promotes neuronal survival, regulates circadian rhythm via SCN, inhibits NF-kB-mediated inflammation, and modulates gut-brain axis signaling.
Research Protocols
For research purposes only. Not medical advice.
Research protocols use 50-200mcg intranasally 1-3 times daily. IV research doses used in ARDS studies were 100-300pmol/kg/min. Subcutaneous protocols not well-established due to rapid degradation.
Research Notes
Clinical Research Status
VIP has been studied extensively in the context of CIRS by Dr. Ritchie Shoemaker and others, with intranasal administration showing improvements in inflammatory markers and pulmonary artery pressures. Research in pulmonary hypertension has demonstrated VIP's ability to reduce pulmonary vascular resistance and improve exercise capacity in small clinical trials. It is not FDA-approved for any indication, and its use remains investigational with ongoing debate about optimal dosing protocols.
Key Published Findings
Studies demonstrate VIP's ability to downregulate inflammatory cytokines including TGF-beta, MMP-9, and complement split products C3a and C4a in CIRS patients. In pulmonary hypertension models, VIP reduces right ventricular systolic pressure and pulmonary vascular remodeling through cAMP-mediated smooth muscle relaxation. Neuroprotective properties have been documented in models of Parkinson's disease and Alzheimer's disease through anti-inflammatory and anti-apoptotic mechanisms.
Safety Profile
VIP is generally well-tolerated at therapeutic doses, with the most common side effects being nasal congestion, flushing, and transient hypotension due to its vasodilatory properties. Diarrhea and abdominal cramping may occur at higher doses, reflecting its original physiological role in gut motility regulation. Caution is warranted in patients with existing hypotension or those on antihypertensive medications due to additive blood pressure lowering effects.
Comparison to Related Compounds
VIP belongs to the secretin/glucagon superfamily and shares structural homology with PACAP (Pituitary Adenylate Cyclase-Activating Polypeptide), though VIP has greater selectivity for VPAC1 and VPAC2 receptors. Unlike synthetic vasodilators, VIP provides combined anti-inflammatory and vasodilatory effects through a single molecular pathway. Compared to other CIRS treatments in the Shoemaker protocol, VIP is typically used as a final-step intervention after other markers have been normalized.
Community Observations
Patients using VIP for CIRS report improvements in fatigue, cognitive function, and respiratory symptoms, often describing it as the final piece in their recovery protocol. Sourcing pharmaceutical-grade VIP remains challenging, and proper cold-chain storage is critical for maintaining peptide stability. Some users report rebound symptoms upon discontinuation, suggesting the need for gradual tapering or ongoing maintenance dosing.
Half-Life
~1-2 minutes (IV); ~30 min (intranasal)
Reconstitution
Sterile saline for IV; saline for nasal spray
Storage
Lyophilized
Store at -20C. Extremely sensitive to degradation.
Reconstituted
Prepare fresh. Use within hours of reconstitution.
US Legal Status
Also Known As
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