OnePin Peptide Library · Immune
VIP
Vasoactive Intestinal Peptide · Aviptadil
VIP (Vasoactive Intestinal Peptide) is a 28-amino acid neuropeptide that functions as a potent vasodilator, bronchodilator, and immunomodulator. It is endogenously produced in the gut, pancreas, brain, and immune cells, acting through VPAC1 and VPAC2 receptors to regulate vascular tone, smooth muscle relaxation, immune cell differentiation, and circadian rhythm maintenance. VIP has been studied in the context of pulmonary arterial hypertension, chronic inflammatory respiratory illness, mast cell activation, neuroinflammation, and GI motility disorders. In peptide protocols, VIP is valued for its anti-inflammatory, bronchodilatory, and neuroprotective properties and is commonly administered as part of the evening GH axis syringe with Tesamorelin and Ipamorelin.
Intranasal: Multiple times daily per CIRS protocol. SubQ: Evening dosing. Very short half-life (~1-2 min IV), nasal route provides more sustained absorption. Use within 2-3 weeks of reconstitution.
Start here. Every protocol below is ordered lowest-first. Begin at the smallest effective dose, hold about a week to assess tolerance, and step up only if needed.
How it works
VIP binds to VPAC1 and VPAC2 receptors, activating adenylate cyclase and increasing intracellular cAMP. This triggers smooth muscle relaxation (vasodilation, bronchodilation), inhibition of pro-inflammatory cytokine release from macrophages and T-cells, mast cell stabilization, and modulation of Th1/Th2 immune balance toward anti-inflammatory Th2 response. VIP also acts as a neurotransmitter and neuromodulator in the central and enteric nervous systems, regulating circadian clock function in the suprachiasmatic nucleus, GI motility, and pancreatic secretion. In immune cells, VIP shifts macrophage polarization from pro-inflammatory M1 to anti-inflammatory M2 phenotype. The methionine at position 17 is critical for receptor binding but is oxidation-sensitive, which creates specific handling and mixing requirements.
VIP binds to VPAC1 and VPAC2 receptors, activating adenylate cyclase and increasing intracellular cAMP. This triggers smooth muscle relaxation (vasodilation, bronchodilation), inhibition of pro-inflammatory cytokine release from macrophages and T-cells, mast cell stabilization, and modulation of Th1/Th2 immune balance toward anti-inflammatory Th2 response. VIP also acts as a neurotransmitter and neuromodulator in the central and enteric nervous systems, regulating circadian clock function in the suprachiasmatic nucleus, GI motility, and pancreatic secretion. In immune cells, VIP shifts macrophage polarization from pro-inflammatory M1 to anti-inflammatory M2 phenotype. The methionine at position 17 is critical for receptor binding but is oxidation-sensitive, which creates specific handling and mixing requirements.
What to expect
Days 1-7: Vasodilatory effects (warmth, mild flushing) may be noticed immediately, particularly at higher doses. Respiratory improvements may begin. GI motility effects within first week.
Weeks 2-4: Anti-inflammatory effects become more consistent. Respiratory function improvements stabilize. Sleep quality may improve due to circadian rhythm support.
Weeks 4-12: Cumulative immunomodulatory effects. Chronic inflammatory markers may improve. Best assessed through symptom tracking and inflammatory marker labwork (CRP, ESR, cytokine panels).
Evidence
The honest take
CIRS treatment
Dr. Shoemaker's protocol uses VIP nasal spray as a final step in CIRS treatment. Published case series show improvements in inflammatory markers. Not FDA-approved for CIRS. The most established clinical application for VIP.
Human clinical trial data with inhaled VIP showing improved pulmonary hemodynamics. Mechanism (pulmonary vasodilation) is well-supported. Limited sample sizes.
Preclinical data supports VIP-mediated mast cell stabilization and reduced histamine release. Relevant for mast cell activation conditions. Not a validated mast cell treatment.
Interactions & stacking
What's safe to combine, and what belongs in a separate pin.
Safe & synergistic
Keep separate
Side effects & safety
Commonly reported
- Nasal congestion (vasodilation of nasal mucosa)
- Mild flushing or warmth
- Transient blood pressure decrease (vasodilation)
- Loose stools or increased GI motility
Less common & notes
- VIP is a potent vasodilator and can cause hypotension, particularly in volume-depleted individuals or those on blood pressure medications.
- Diarrhea at higher doses due to GI smooth muscle effects.
- Rarely, headache from vasodilation.
- Start at low dose and titrate up.
- Contraindicated in individuals with significant hypotension.
- Monitor blood pressure during titration.
Pharmacokinetics
Storage. CRITICAL: Methionine-17 is oxidation-sensitive. Protect from light at all times. Reconstitute with BAC water (pH 5-7 acceptable). Refrigerate at 2-8C. Stable for 14-21 days after reconstitution in SubQ solution. Reconstitute fresh every 2-3 weeks regardless of remaining volume. Do not expose to direct light during storage or injection preparation. Unreconstituted lyophilized powder is more stable (store frozen -20C).
Regulatory status
VIP is available through compounding pharmacies by prescription. Not FDA-approved for any injectable indication. Available as a research peptide. Not specifically listed on WADA prohibited list. Used clinically in some countries for specific indications.
Put it to work
Calculate, log & track
Open VIP straight into OnePin with your vial and dose pre-filled, then let it handle the syringe math and remind you before the vial runs out.
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The guide & community
The complete VIP walkthrough, real protocol discussion and coaching live inside the BlessUp community on Skool.
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