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VIP

aka vasoactive intestinal polypeptide, aviptadil, Zyesami

VasoactiveAnti-inflammatoryVasodilationImmune ModulatorSleepNeuroprotection

Last reviewed April 27, 2026 by Doserr editorial team · 16 references on this page

Information on this page is sourced from published research and is for educational purposes only. It does not constitute medical advice.

TL;DR

  • What it is: A 28-amino-acid endogenous neuropeptide that acts as a vasodilator, immune modulator, and circadian clock regulator.
  • What it's used for: Primarily used in the CIRS and mold illness community via Shoemaker protocol, no FDA approval exists.
  • Evidence level:limitedSmall uncontrolled human pilots only, no published randomized controlled trial.

Dose at a glance

BeginnerCommonHigher end
Per dose50 mcg (1 spray)50 mcg (1 spray)50 mcg (1 spray)
Daily total50-100 mcg (1-2 sprays)200 mcg (4 x 50 mcg sprays)300 mcg (6 sprays)
Schedule1-2x daily (1-2 sprays)4x daily (4 sprays)6x daily (6 sprays)
Cycle length6+ months (as part of full protocol)6-18 months>12 months

Synthesized from community-reported ranges. Not a recommendation. Route varies by compound — see Common route in What people report below.

Half-life
Approximately 1-2 minutes in plasma due to enzymatic degradation by DPP-IV, neutral endopeptidase, and aminopeptidases (PMC4484298). No validated human pharmacokinetic study exists for the intranasal route. Short IV half-life explains why intranasal delivery is preferred in community use.
Typical dose range
Doses below are from published research, not recommendations. Inhaled VIP: 100 mcg acute dose, 200 mcg/day (4 x 50 mcg inhalations) in a 24-week PPH trial (n=8, PMID: 12727925). Inhaled VIP in sarcoidosis: dose not reported in abstract, 4-week trial in 20 participants (PMID: 20442436). Shoemaker CIRS case series: intranasal 50 mcg 4x daily, titrated over 18 months (n=20, DOI: 10.4236/health.2013.53053, not indexed in PubMed).
Route
Inhaled/aerosolized in formal pulmonary trials. Intranasal instillation in Shoemaker CIRS series. IV used in historical acute studies and COVID-19 trials.
Evidence tier
limited

Animal or in-vitro studies only — no published human efficacy data.

What the research shows

Each topic links to the studies behind it. Click a topic to expand.

What we don't know yet

  1. CIRS is not a recognized diagnosis in conventional medicine, the primary rationale for intranasal VIP in community use rests entirely on Shoemaker's unvalidated framework
  2. No randomized controlled trial of VIP has been published as of mid-.
  3. Intranasal pharmacokinetics in humans are not characterized in peer-reviewed literature, plasma half-life is ~1-2 min from IV/enzymatic data (PMC4484298)
  4. Shoemaker's multi-step protocol prerequisites make it impossible to isolate VIP's individual effect from prior interventions
  5. Long-term safety of chronic intranasal VIP use has not been evaluated in a controlled study, theoretical concern exists for impaired intracellular pathogen defense with sustained immune suppression (PMC2730848)
  6. Community reports of concerns about VIP use after HBOT have no published mechanistic or clinical data to evaluate

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