VIP
VIP (vasoactive intestinal peptide) is a 28-amino-acid neuropeptide with broad anti-inflammatory and vasodilatory signalling; its synthetic form, aviptadil, has been tested in small phase II trials in sarcoidosis and pulmonary hypertension.
Research protocols in this catalog use 50 mcg subcutaneously to start, with a range of 50-200 mcg — note that the published human trials used the inhaled route, not subcutaneous injection.
Best for
Adults researching anti-inflammatory neuropeptide signalling, including the CIRS/mold-illness protocols where VIP is most often discussed.
Human evidence is limited to small phase II cohorts in specific lung diseases; the CIRS use is off-label, unstudied in controlled trials, and should be run with a clinician.
What to expect
Vasodilatory and flushing effects are immediate and short-lived, reflecting a plasma half-life measured in minutes. Anti-inflammatory changes in the sarcoidosis trial were measured after four weeks of daily inhaled dosing; nothing comparable has been published for the subcutaneous route.
Pairs with
In CIRS protocols it is typically the last step after binders, mycotoxin clearance, and remediation of the exposure — sequencing that comes from clinical convention rather than trial evidence. No peptide combination has been studied, and pairing it with other vasodilators or blood-pressure-lowering agents compounds the vasodilatory effect.
Subcutaneous injection, once daily in the morning; some protocols run it only two to three times weekly. The catalog reference starts at 50 mcg with a range of 50-200 mcg (50 mcg starting, 100 mcg standard, 200 mcg higher).
The default 5 mg vial reconstituted with 5 mL of bacteriostatic water gives 1 mg/mL, so 50 mcg is 5 units on an insulin syringe and 200 mcg is 20 units. Start at the low end: the peptide has a very short half-life and vasodilatory effects are dose-dependent.
Research reference only.
- How often
- Daily
- When
- Morning
- Route
- Subcutaneous
- Vial & water
- 5 mg vial in 5 mL = 1 mg/mL · 50 mcg = 5 units on a U-100 syringe
- Cycle
- Protocols vary; very short half-life — often daily to a few times weekly.
The same numbers the goodtides app and the Dose Calc use — a research reference, not a prescription. Responses are individual; research protocols start at the low end.
Vasoactive intestinal peptide is an endogenous 28-amino-acid neuropeptide of the secretin/glucagon superfamily, released by neurons throughout the gut, lung, and central nervous system.
VIP is not FDA-approved for any of these uses.
It acts at the VPAC1 and VPAC2 G-protein-coupled receptors, raising intracellular cAMP; the downstream consequences include smooth-muscle relaxation (hence pulmonary and systemic vasodilation and bronchodilation), and a distinctly immunoregulatory profile in which VIP suppresses pro-inflammatory cytokine production by macrophages and pushes T-cell populations toward a regulatory phenotype. The strongest human data comes from two small phase II studies of the synthetic form, aviptadil.
In a 2010 open-label trial, 20 patients with biopsy-proven active sarcoidosis inhaled nebulized VIP for four weeks; treatment was safe and well tolerated, significantly reduced TNF-alpha production by cells from bronchoalveolar lavage fluid, and increased lavage CD4+CD127-CD25+ regulatory T cells, with companion in vitro work showing VIP converting naive CD4+CD25- cells into FoxP3+ regulatory T cells. The authors described it as the first demonstration of an immunoregulatory effect of VIP in humans.
In a 2008 study, 20 patients with pulmonary hypertension inhaled a single 100 mcg dose during right-heart catheterization; aviptadil produced a small, temporary, but selectively pulmonary vasodilation with improved stroke volume and mixed venous oxygen saturation, without systemic blood-pressure effects or side effects — the authors themselves called the effect modest and short-lived. Aviptadil was subsequently studied in COVID-19 respiratory failure.
Two caveats belong in any honest summary: these are small, mostly open-label cohorts rather than definitive trials, and both used inhalation, whereas the subcutaneous dosing common in wellness protocols has no comparable published evidence.
- Half-life
- ~1-2 min in plasma — extremely short; rapidly degraded by circulating peptidases
- Peak
- Minutes after dosing; hemodynamic effects in the inhaled pulmonary-hypertension study were immediate and transient
- Absorption
- Inhaled (nebulized) in the published trials; subcutaneous or intranasal in wellness protocols. Not orally active — it is degraded in the gut.
- Bioavailability
- Not established for the subcutaneous route; oral is effectively zero
References3
Log every dose, count every vial, and verify your batches — free in the goodtides app.
This page is educational reference material about compounds studied in research settings. It is not medical advice, and nothing here is a recommendation to buy, possess, or use any compound. Research findings described are from published literature; individual compounds may not be approved for human use. Talk to a licensed clinician about anything that affects your health.