ModerateCaution
L-Citrulline
L-citrulline can increase nitric oxide-mediated vasodilation and may add to VIP-related flushing or low blood pressure.
Recommendation: Avoid combining if prone to hypotension, syncope, or using antihypertensive drugs.
VIP (Vasoactive Intestinal Peptide)
Peptide ·Insufficient evidence ·Reviewed May 2026
VIP is an endogenous 28-amino-acid neuropeptide with vasodilatory, bronchodilatory, secretory, and immunomodulatory effects through VPAC receptors. Intranasal, inhaled, or injectable wellness use is not FDA-approved, although related aviptadil formulations have been studied for pulmonary and inflammatory disorders. Evidence for CIRS or general immune-repair protocols is limited and off-label.
What it's good for
What to watch for
- Flushing
- Low blood pressure
- Tachycardia or palpitations
- Hypotension or syncope tendency
- Unstable heart rhythm or severe cardiovascular disease without specialist care
The bottom line
Evidence rating insufficient. Most-documented uses: studied for pulmonary immune modulation, potent vasodilatory signaling, mucosal and neuroimmune research interest. 3 sources indexed (1991–2010), with 3 interaction records on file.
The science
How it works, mechanistically.
Core mechanism
VIP activates VPAC1 and VPAC2 G-protein-coupled receptors, increasing cAMP signaling in immune, epithelial, smooth-muscle, and nervous-system tissues. This can relax vascular and airway smooth muscle, influence mucosal secretion, and shift inflammatory cytokine patterns. These effects also explain risks such as flushing, hypotension, tachycardia, headache, and diarrhea.
Class
VPAC receptor neuroimmune and vasodilatory peptide
Found in food
None as a dietary supplement
Low-status signs
No recognized dietary deficiency state exists for this peptide
Dosing
Dosing & protocol.
Common range
No FDA-approved human dose for wellness or CIRS; inhaled research protocols are study-specific
Recommended form
Investigational inhaled or intranasal product only under medical supervision
Peptides are generally not reliably orally bioavailable unless a specific studied oral formulation is used. Human use of research-grade products is not appropriate.
Forms
Forms & what to buy.
Ranked by evidence and value.
Investigational Inhaled VIP Recommended
Targets airway and pulmonary tissues; systemic absorption can still occur. Can cause hypotension or flushing.
Intranasal Compounded VIP
Used off-label in some protocols; not FDA-approved. Nasal irritation and variable absorption are concerns.
Injectable Research VIP
Systemic vasodilatory peptide exposure is high risk. Nonsterile products are unsafe.
Cost
What it actually costs.
Real-world pricing across three quality tiers. Assumes Investigational Inhaled VIP.
BudgetBest value
$60 /mo
$2.00 per dose
Mid
$180 /mo
$6.00 per dose
Premium
$450 /mo
$15.00 per dose
Research-market pricing is not a dosing recommendation; human use is not FDA-approved unless specifically stated. Updated 2026-06-04.
Goals
Goal-based dosing.
Pulmonary Immune Research
Dose: Protocol-specific inhaled dosing1,2
Timing: Study protocol only
Small human studies do not establish routine use.
CIRS or Mold-Illness Protocols
Dose: No FDA-approved dose
Timing: Per clinician if used
Evidence is limited and diagnosis should be rigorous.
General Anti-Inflammatory Wellness
Dose: No approved dose
Timing: Not applicable
Vasodilatory adverse effects can be clinically important.
Why people use it
Symptoms it's matched to.
Where this appears in the symptom-to-supplement map, ranked by relevance.
Inflammatory flares
8% relevance
VIP has immunoregulatory biology but limited clinical evidence.1,3
InflammationInsufficient evidenceAvoid self-treatment
Do not replace diagnosed disease care.
Brain fog
5% relevance
CIRS-related claims are off-label and weakly evidenced.
CognitiveInsufficient evidenceSpecialist-directed only
Rule out common causes.
Shortness of breath
5% relevance
Pulmonary studies exist, but dyspnea can be urgent and VIP is not standard treatment.2
ImmuneInsufficient evidenceMedical evaluation
Seek care for respiratory symptoms.
Safety
Full safety detail.
Side effects
- Flushing
- Low blood pressure
- Tachycardia or palpitations
- Headache
- Nasal irritation
- Diarrhea
- Dizziness
Contraindications
- Hypotension or syncope tendency
- Unstable heart rhythm or severe cardiovascular disease without specialist care
- Pregnancy and breastfeeding
- Active severe asthma, infection, or respiratory distress without medical care3
- Use of nonsterile compounded or research-grade products
Interactions
Interaction records.
ModerateCaution
Magnesium Glycinate
Magnesium can lower blood pressure in some users and may add to VIP-related dizziness.
Recommendation: Monitor blood pressure in any supervised context; avoid self-use.
InfoCaution
Melatonin
Melatonin-related sleepiness may worsen dizziness from VIP-related hypotension.
Recommendation: Avoid driving or hazardous activity if dizziness occurs.
Search all 3 interaction records for VIP (Vasoactive Intestinal Peptide) →
Sources
Sources, by evidence tier.
Numbered references. Citations throughout the page link here.
Randomized controlled trials
2- 1Inhaled vasoactive intestinal peptide exerts immunoregulatory effects in sarcoidosisNeeds sourceNo linkPrasse A et al. · American Journal of Respiratory and Critical Care Medicine · 2010
Inhaled VIP altered immune readouts
- 2Vasoactive intestinal peptide as a new drug for treatment of primary pulmonary hypertensionNeeds sourceNo linkPetkov V et al. · Journal of Clinical Investigation · 2003
Pulmonary hemodynamic effects were observed
Reviews & position papers
1- 3Vasoactive intestinal peptide in the lungNeeds sourceNo linkSaid SI · Annals of the New York Academy of Sciences · 1991
VIP is active in lung tissues
Keep exploring
Deep dives & adjacent profiles.
This page is educational. Do not start, stop, or change a supplement or medication based on it without checking with a qualified healthcare professional.
Use this with your stack
VIP (Vasoactive Intestinal Peptide) in NutriStack.
Add it to your stack, see how it interacts with everything else you take, and get a Stack Score that updates the moment it does.