VIP: Vasoactive Intestinal Peptide Research Guide (2026)
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Introduction (research-only scope)
VIP, vasoactive intestinal peptide, is a 28-amino-acid neuropeptide found throughout the nervous, gastrointestinal and immune systems. Unlike most compounds in this catalog it is a genuine endogenous signalling molecule with a well-mapped receptor system, and it has been through clinical trials under the name aviptadil. This guide covers the receptors, the immune biology and what those trials tested.
Research use only. The material described here is a laboratory reagent for in-vitro research by qualified professionals. It is not a medicine, supplement, cosmetic ingredient or veterinary product, is not for human or animal use, and nothing on this page is medical advice or a claim of effect in any person.
What is VIP?
VIP (molecular mass 3326.82, CAS 37221-79-7) belongs to the secretin/glucagon peptide superfamily and shares substantial homology with PACAP, which is why the two are studied together. Peptra Labs supplies it as a lyophilised research reagent, 10 mg per vial.
How the reported mechanism works
VPAC1 and VPAC2 receptors
VIP signals through two class B G protein-coupled receptors, VPAC1 and VPAC2, primarily through cAMP. Receptor distribution differs by tissue, which is the basis for the selectivity questions that dominate the pharmacology literature.
Immune functions
The 2013 review in Amino Acids sets out its pleiotropic immune role, including effects on macrophage and T-cell signalling, which is why it appears in immunology assays as well as neuroscience work.
What the published evidence covers
The endogenous biology is solid textbook material. The therapeutic record is more instructive: synthetic VIP, as aviptadil, was tested intravenously in COVID-19-associated hypoxaemic respiratory failure in the TESICO trial published in Lancet Respiratory Medicine in 2023, and that programme did not produce an approved product for the indication. It is a useful reminder that a well-characterised endogenous peptide does not automatically become a successful therapeutic.
How to verify a VIP research peptide is real and pure
Two tests answer two different questions: mass spectrometry confirms identity (expected molecular mass 3326.82), HPLC quantifies purity. Our specification is at least 98%. Check the batch number printed on your vial against the lab reports archive: where a batch has been tested, its report is published there and links to the testing laboratory’s own verification page. If your batch is not listed yet, ask us for its documentation before use; a “typical” certificate is not evidence for a specific vial. See how to read a certificate of analysis.
Storage and reconstitution
Store the lyophilised material sealed, dry and protected from light at 2 to 8 °C for routine laboratory use, colder for long-term archiving. After reconstitution with bacteriostatic water, keep refrigerated and use within the window your protocol defines; repeated freeze-thaw cycles degrade peptides. General handling for all our reagents is in the peptide storage protocol.
Regulatory status
VIP is not an authorised medicine in the European Union, the United Kingdom or the United States in the form supplied here; certain VIP-containing products exist in some jurisdictions for narrow indications, and the reagent supplied here is not any of them. It is not named individually on the WADA Prohibited List, but section S0 covers substances without approval for human therapeutic use. Research-grade material supplied here is not a medicine and is for in-vitro laboratory use only. The wider framework, including anti-doping status, is described in the peptide risk profile.
Why labs choose our VIP
Batch-numbered vials, published reports where a batch has been tested, shipping from an EU warehouse with tracking (no customs inside the EU) and prices shown with VAT included. Product page: VIP 10 mg. Country-by-country sourcing questions are covered in the buyer guide Buy VIP in Europe.
References
- Delgado M, Ganea D. Vasoactive intestinal peptide: a neuropeptide with pleiotropic immune functions. Amino Acids. 2013. PubMed 22139413
- Intravenous aviptadil and remdesivir for treatment of COVID-19-associated hypoxaemic respiratory failure (TESICO). Lancet Respir Med. 2023. PubMed 37348524