NeuropeptideEditorially reviewed · 28. Mai 2026

VIP

Also known as Vasoaktives Intestinales Peptid, Vasoactive Intestinal Peptide, Aviptadil et al.

not approvedEvidence · early clinical studies3 studies cited

Structure · schematic

Peptide chain of 28 amino acids · Neuropeptid

Sequence

HSDAVFTDNYTRLRKQMAVKKYLNSILN-NH₂

Schematic representation of the amino acid chain — not a chemical structural formula. Each node represents one amino acid (shown truncated).

Research areas*

Immunomodulation
Cognition

* Contexts in which the peptide has been scientifically studied — not assured or recommended effects.

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Mechanism of action

  • VIP is a 28-amino-acid neuropeptide of the secretin/glucagon superfamily, produced throughout the nervous system as well as in intestinal, respiratory and immunological tissues.
  • VIP binds the G-protein-coupled receptors VPAC1 and VPAC2, which via cAMP signalling pathways leads to vasodilation, bronchodilation and pronounced immunomodulation.
  • Immunologically, VIP inhibits the production of pro-inflammatory cytokines (TNF-α, IL-6, IL-12) and promotes regulatory T cells (Tregs) as well as anti-inflammatory mediators (IL-10).
  • In the lung and gut, VIP also acts as a neuroprotective and epithelium-protecting mediator.
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Research status

  • Aviptadil (synthetic VIP) has been studied clinically mainly in pulmonary arterial hypertension (inhaled) and in COVID-19-associated studies of acute respiratory failure.
  • A randomised Phase II study (Lancet Respiratory Medicine, 2023) in COVID-19-related hypoxaemic respiratory failure showed no significant difference in the primary endpoint, although earlier uncontrolled studies had shown positive signals.
  • In the MCAS and long-COVID community, VIP is intensively discussed; controlled studies for these indications are pending.
  • A further research focus is VIP's role in mast-cell regulation and intestinal inflammation.

Evidence level

PreclinicalEarly clinicalEstablished
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Cited studies

  1. 2006
    VIP and PACAP modulate T cell function and inhibit immune-mediated inflammation
  2. 2008
    Inhaled aviptadil (VIP) in pulmonary arterial hypertension: a randomized pilot study
  3. 2023
    Vasoactive intestinal peptide in COVID-19-associated acute hypoxaemic respiratory failure: a randomised controlled trial
§ 4

Known risks

  • 01Hypotension: pronounced vasodilatory effect — drop in blood pressure possible with parenteral administration
  • 02Tachycardia as a reflex response to vasodilation
  • 03Flushing, headache with systemic use
  • 04No established dosing protocols for safe non-clinical use
  • 05The randomised COVID-19 study showed no significant primary-endpoint effect
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Frequently asked questions

What is VIP?

VIP is a 28-amino-acid neuropeptide of the secretin/glucagon superfamily, produced throughout the nervous system as well as in intestinal, respiratory and immunological tissues.

What type of peptide is VIP?

VIP belongs to the Neuropeptide class.

Is VIP legal in Germany?

VIP is not approved as a medicine in Germany. Obtaining it outside clinical studies is legally problematic.

Where can I buy VIP?

Peptica sells nothing and names no sources. VIP is "not approved" in Germany; obtaining unapproved substances outside clinical studies is illegal and carries quality and safety risks.

Is VIP banned in sport (WADA)?

VIP is currently not on the WADA Prohibited List.

What are the known risks of VIP?

Documented risks include: Hypotension: pronounced vasodilatory effect — drop in blood pressure possible with parenteral administration; Tachycardia as a reflex response to vasodilation. This is not a complete safety assessment and not medical advice — see the risks section for the full list.

How well researched is VIP?

The evidence is classified as “early clinical studies”. 3 studies are cited on this page.

What is the molecular weight of VIP?

VIP has a molar mass of about 3326.8 Da, with a plasma half-life of ~1–2 minutes.

Which peptides are related to VIP?

Closely related entries: Selank, DSIP. A direct side-by-side comparison is available via the compare function.

Related entries

Legal status

Germany

not approved

Austria

not approved

Switzerland

not approved

EU

not approved

USA

not approved

Canada

not approved

Legal status varies by country and can change. This is not legal advice.

Sources & methodology

  • 3 peer-reviewed studies cited, linked to PubMed where available.
  • Molecular data verified against PubChem and primary literature. PubChem CID 16132300
  • Editorial standard: no dosage guidance, no sources, evidence level stated explicitly.

Last editorially reviewed: 28 May 2026

Legal assessment

Aviptadil is not approved as a medicine in the EU. Clinical studies are ongoing within regulated trial programmes. VIP is not on the WADA Prohibited List. Import for purposes other than scientific ones may fall under the German Medicines Act (AMG).

Important notice

This site is intended solely for factual, scientifically oriented information about peptides. It does not constitute medical advice, does not replace a consultation with a doctor and contains no recommendations for use in humans.

This site does not sell any substances and names no sources for unapproved substances. For medical questions, please consult qualified medical professionals.

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Community notes

Note: These posts are user opinions and not medical advice. Posts containing dosages, therapeutic claims or purchase recommendations are removed. All entries are manually reviewed before publication.