VIP

Neuropeptide / immune modulator · Also known as Vasoactive Intestinal Peptide, Vasoactive Intestinal Polypeptide, Aviptadil

What is vip?

A 28-amino-acid neuropeptide naturally produced in the gut, pancreas, and brain. It acts as a potent vasodilator, anti-inflammatory agent, and immune regulator, with particular relevance in treating chronic inflammatory response syndrome (CIRS) from mold exposure.

VIP was first isolated in 1970 from porcine intestinal tissue. It belongs to the glucagon/secretin superfamily and plays wide-ranging roles in vasodilation, smooth muscle relaxation, and immune regulation. It has been used in CIRS treatment protocols, most notably by Dr. Ritchie Shoemaker, where VIP nasal spray is the final step in restoring immune balance after mold illness. Inhaled VIP has also shown promise for pulmonary hypertension.

Key takeaway: VIP is a naturally occurring neuropeptide used in some CIRS/mold illness treatment protocols and studied for pulmonary hypertension. Clinical evidence comes primarily from one practitioner's protocol and has not been validated in large independent trials.

Benefits & evidence

CIRS/mold illness treatment Moderate confidence
Anti-inflammatory High confidence
Vasodilation High confidence
Pulmonary hypertension Preliminary confidence
Neuroprotection Preliminary confidence
Gut motility regulation Moderate confidence

How it works

VIP binds to two G protein-coupled receptors, VPAC1 and VPAC2, triggering activation of adenylyl cyclase and increasing intracellular cAMP and PKA activity. This cascade produces vasodilation (50 to 100 times more potent than acetylcholine on a molar basis), smooth muscle relaxation in the airways and gut, and suppression of pro-inflammatory cytokines including TNF-alpha and IL-6.

In the context of CIRS, VIP helps normalize the dysregulated innate immune response caused by chronic biotoxin exposure. It reduces markers like C4a, TGF-beta-1, and MMP-9 while restoring regulatory T cell function. In pulmonary hypertension studies, inhaled VIP reduced pulmonary artery pressure and improved right ventricular function. It also supports circadian rhythm regulation through its presence in the suprachiasmatic nucleus of the hypothalamus.

Dosing information

Typical dosing protocol
Starting dose

50 mcg nasal spray 4x/day

Month 1
Maintenance dose

50-100 mcg nasal spray 4x/day

1-3 months or as directed

Administered as a nasal spray, alternating nostrils. Used as the final step in the Shoemaker CIRS protocol after other inflammatory markers have been addressed. This dose range has been used in clinical practice. Lipase levels should be monitored due to a small risk of pancreatitis. For pulmonary hypertension, inhaled VIP was studied at 200 mcg/day divided into 4 inhalations.

Side effects

Most side effects tend to improve as your body adjusts.

Nasal irritation Common
Mild headache Common
Dizziness Moderate
Palpitations Moderate
Transient blood pressure drop Moderate
Pancreatitis (requires lipase monitoring) Rare

Research (10 studies)

[Mechanism of Quzhou Aurantii Fructus in treating rats with functional dyspepsia based on gut microbiota and metabolomics]. Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica · 2026