VIP is a neuropeptide that functions as a neurotransmitter, hormone, and immunomodulator. Endogenously produced; also available as nasal spray for therapeutic use.
Mechanism — Binds VPAC1 and VPAC2 receptors to drive vasodilation, immunosuppression of Th1/Th17 pathways, and circadian regulation. Levels are commonly low in mold-related illness and CIRS, where its restoration is a Shoemaker-protocol step.
Use case — Investigational for CIRS, chronic fatigue, autoimmune flares, and persistent inflammation. Typical nasal dosing 50 mcg 4x/day after upstream toxin removal.
Caveats — Requires biotoxin clearance and other CIRS protocol steps first — VIP alone in a contaminated environment can worsen things. Compounded prescription in the US.