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Neurological — NeuropeptideResearch Use

VIP

Also known as: Vasoactive Intestinal Peptide · Aviptadil

MW

3326.82 Da

Amino Acids

28 AA

Half-Life

2 minutes (rapid)

Route

Intranasal, SubQ, IV

CAS

37221-79-7

Formula

C147H237N43O43S

Amino Acid Sequence

HSDAVFTDNYTRLRKQMAVKKYLNSILN-NH2

Mechanism of Action

VIP (Vasoactive Intestinal Peptide) is a 28-amino acid neuropeptide that binds VPAC1 and VPAC2 receptors (Gs-coupled → adenylyl cyclase → cAMP). It is one of the most potent endogenous vasodilators.

VASODILATION: Potent relaxation of vascular and bronchial smooth muscle. Pulmonary vasodilation is the basis for aviptadil (synthetic VIP) use in pulmonary hypertension and ARDS.

ANTI-INFLAMMATORY: Potent immune regulation — inhibits Th1 responses, reduces TNF-α, IL-6, IL-12 production by macrophages and dendritic cells. Promotes Th2/Treg shift. This makes VIP relevant for autoimmune conditions and chronic inflammatory response syndrome (CIRS).

GI FUNCTION: Stimulates water and electrolyte secretion, relaxes GI smooth muscle, promotes intestinal motility. VIP-secreting tumors (VIPomas) cause profuse watery diarrhea.

NEUROPROTECTION: VIP is a neuropeptide with CNS distribution. Promotes neuronal survival and synaptic function.

CIRCADIAN: Regulates circadian rhythm in the suprachiasmatic nucleus.

Dosing Protocol

Low Dose

███ – ███ mcg/day

Standard Dose

███ mcg/day

High Dose

███ – ███ mcg/day

Dosing protocols are for paid members

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Frequency

Daily SubQ or intranasal.

Half-Life

2 minutes (rapid)

Reconstitution Guide

Full reconstitution protocol with BAC water volumes, concentration math, and units-to-draw per dose is available on the Clinical plan.

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Clinical Warnings

Vasodilation → hypotension risk, especially with antihypertensives.

GI effects (diarrhea, cramping).

Short half-life (~2 min IV).

IV requires clinical setting.

Tachycardia possible.

Not FDA approved for most indications.

Contraindications

Absolute

Pregnancy

Relative Cautions

Hypotension

Diarrheal conditions

Side Effect Profile

Mild

  • Nasal congestion
  • Mild diarrhea
  • Flushing

Moderate

  • Hypotension
  • Tachycardia
  • Headache

Severe (Rare)

  • Severe hypotension

Synergistic Peptides

KPVBPC-157LL-37

Common Stacks

KPV

BPC-157

Research Status

MODERATE. PMID 19416873 (Abad 2010): Anti-inflammatory mechanisms in autoimmune disease. PMID 15148335 (Hamidi 2004): Aviptadil pulmonary hypertension Phase II. COVID-19 ARDS data. Well-characterized biochemistry.

Frequently Asked Questions

How does VIP work?

VIP (Vasoactive Intestinal Peptide) is a 28-amino acid neuropeptide that binds VPAC1 and VPAC2 receptors (Gs-coupled → adenylyl cyclase → cAMP). It is one of the most potent endogenous vasodilators. VASODILATION: Potent relaxation of vascular and bronchial smooth muscle. Pulmonary vasodilation is the basis for aviptadil (synthetic VIP) use in pulmonary hypertension and ARDS. ANTI-INFLAMMATORY: Potent immune regulation — inhibits Th1 responses, reduces TNF-α, IL-6, IL-12 production by macrophag

What is the standard dose of VIP?

VIP dosing protocols are available with a ClinPep Clinical subscription. Dosing varies by indication and patient factors — consult a licensed healthcare provider. General frequency: Daily SubQ or intranasal.

What is the half-life of VIP?

The half-life of VIP is 2 minutes (rapid). This determines optimal dosing frequency and timing.

Who should not use VIP?

VIP is absolutely contraindicated in: Pregnancy. Use with caution in: Hypotension; Diarrheal conditions.

What are the side effects of VIP?

Common mild side effects include: Nasal congestion, Mild diarrhea, Flushing. Moderate effects: Hypotension, Tachycardia, Headache.

What peptides stack well with VIP?

VIP is commonly stacked with: KPV, BPC-157, LL-37.

How do you reconstitute VIP?

VIP is reconstituted with bacteriostatic water. Exact volumes, concentrations, and units-to-draw calculations are available in the ClinPep Clinical plan. Always follow your compounding pharmacy's instructions.

How long should you cycle VIP?

VIP cycle protocols vary by indication. Detailed cycle length, on/off schedules, and monitoring guidelines are available with ClinPep Clinical access. Consult your healthcare provider for personalized cycling guidance.

References & Citations

10 PubMed studies · 3 clinical trials

Aviptadil Therapy in Acute Respiratory Distress Syndrome Patients: A Systematic Review and Meta-analysis.

Udupa Ashritha A, Todur Pratibha, Chaudhuri Souvik, Gupta Nitin et al.. Indian journal of critical care medicine : peer-reviewed, official publication of Indian Society of Critical Care Medicine. 2025

PubMed: 41368449DOI ↗C — Research Article

Acute respiratory distress syndrome (ARDS) is a life-threatening condition with a high mortality rate despite advances in supportive care. Aviptadil, a synthetic analogue of vasoactive intestinal pept

Octreotide ameliorates Bisphenol A-induced testicular toxicity via autophagy-inflammation pathway modulation.

Morad Basma B, Salem Ola M, El-Esawy Rasha Osama, Abd Elmonem Fleur F. Human & experimental toxicology. 2025

PubMed: 41293964DOI ↗C — Research Article

IntroductionTesticular toxicity commonly manifests as impaired spermatogenesis and testicular atrophy. Bisphenol A (BPA), a commonly used organic plasticizer, negatively affects sperm parameters, horm

Study on the neuroimmune regulatory mechanism of electroacupuncture at Zusanli acupoint for postoperative intestinal paralysis after gastrointestinal surgery.

Xu Jing-Yan, Li Cheng. World journal of gastrointestinal surgery. 2025

PubMed: 41178875DOI ↗C — Research Article

Postoperative intestinal paralysis is common in gastrointestinal surgery, and the study of electroacupuncture mechanisms is of great significance. To explore the neuroimmune regulatory mechanism of el

Amygdalin regulated vasoactive intestinal peptide receptor to protect alveolar epithelial barrier against lung injury induced by influenza a virus.

Song Xueyue, Wang Ting, Ye Miao, Shi Xunlong et al.. Chinese medicine. 2025

PubMed: 41034926DOI ↗C — Research Article

Bitter apricot kernel is a common traditional Chinese medicine used for lung diseases. Previous studies showed that Xuanbai-Chengqi decoction (XCD) containing bitter apricot kernel protected the alveo

Overexpression of colonic VIP ameliorates cognitive function and barrier system damage caused by sevoflurane anesthesia and surgery in aged rats with fragile brain functions.

Liao Huihui, Wang Xinyi, Yang Chenyi, Wang Zixuan et al.. Experimental neurology. 2025

PubMed: 40456433DOI ↗C — Research Article

Surgery and anesthesia may compromise fragile brain function in the elderly, potentially precipitating cognitive decline or Alzheimer's disease (AD) following perioperative neurocognitive disorder (PN

Vasoactive Intestinal Peptide: A Neuropeptide that Plays an Important Role in Parkinson's Disease.

Fan Wenhui, Li Ke, Wang Ruohua, Chen Rongsha et al.. Current neuropharmacology. 2025

PubMed: 40353414DOI ↗C — Research Article

Parkinson's disease (PD) is primarily characterized by rigidity and tremor, which are pathologically associated with α -synuclein aggregation, especially in dopaminergic neurons in the midbrain.

Clinical Efficacy of Transcutaneous Electrical Nerve Stimulation (TENS) in Pediatric Functional Constipation: Impact on Immunological Indicators and Gut Microbiota.

Guo Piao, Zhang Xue Ning, Jin Xin Yu, Xia Wen Juan et al.. Journal of immunology research. 2025

PubMed: 40027592DOI ↗C — Research Article

Objective: This study was conducted to evaluate the effectiveness of transcutaneous electrical nerve stimulation (TENS) in treating pediatric functional constipation (FC) and to explore its mechanisms

A Randomized Comparison of Bencycloquidium Bromide, Mometasone Furoate, and a Combination for Persistent Allergic Rhinitis.

Li Xian, Wang Xueyan, Yang Qintai, Chen Jianjun et al.. The journal of allergy and clinical immunology. In practice. 2025

PubMed: 39746515DOI ↗B — Clinical Trial

Moderate to severe persistent allergic rhinitis (AR) poses a substantial socioeconomic burden. We aimed to establish the superiority of bencycloquidium bromide (BCQB) nasal spray and BCQB combined wit

Registered Clinical Trials

Duvelisib Ameliorates Manifestations of Pneumonia in Established Novel Coronavirus Infection (COVID-19)

NCT04487886COMPLETEDPHASE2

Efficacy and Safety of Stapokibart in Non-Allergic Rhinitis With Eosinophilia Syndrome

NCT07240376NOT_YET_RECRUITINGNA

The Effects of a Long-lasting Infusion of Vasoactive Intestinal Peptide (VIP) on Headache, Cranial Hemodynamic and Autonomic Symptoms in Healthy Volunteers

NCT03989817COMPLETEDNA

Symptom Indications

CIRSMold illnessChronic inflammationGut dysfunctionCircadian disruptionNeuroinflammation

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This information is for educational and research reference purposes only. ClinPep does not provide medical advice, diagnosis, or treatment recommendations. All protocols should be reviewed by a licensed healthcare provider.