Quick answer: Vasoactive intestinal peptide (VIP) is a 28-amino-acid neuropeptide that researchers use to study VPAC1 and VPAC2 receptor signaling. Published work is mostly cell, tissue and preclinical research on cAMP signaling, neuro-immune communication, smooth muscle and airway biology. The evidence is strong for receptor pharmacology and much thinner for anything beyond it.
What is vasoactive intestinal peptide (VIP)?
VIP, also written as vasoactive intestinal polypeptide or the VIP peptide, is a naturally occurring neuropeptide. It belongs to the secretin/glucagon family and is found in the central and peripheral nervous systems, the gut, the airways and immune-associated tissues. It was named after an early observation that it affected blood vessels and was found in intestinal tissue.
It is a short chain of 28 amino acids. That makes it a useful tool for studying how one signaling molecule can act in many different tissues.
How do VPAC1 and VPAC2 receptors work?
VIP acts mainly on two G protein-coupled receptors, VPAC1 and VPAC2. These are proteins on the cell surface that pass a signal inward when a peptide binds. The proposed main route is activation of adenylate cyclase, an enzyme that raises the cell's level of cAMP. cAMP is a "second messenger", a small molecule that relays the signal to other parts of the cell.
The VPAC receptors are named for the two peptides that bind them, VIP and PACAP. This shared receptor system is why VIP is so common in receptor pharmacology work.
What has published laboratory research examined?
cAMP and second messenger signaling
This is the best-supported area. Cell studies use VIP to trigger VPAC receptors and then measure cAMP and downstream gene responses.
Neuropeptide and CNS signaling
Researchers have examined VIP as a neuromodulator, meaning a molecule that adjusts how nerve cells communicate. Work includes neuronal receptor signaling and neuro-immune communication.
Smooth muscle and vascular tone
Tissue and preclinical models have used VIP to study smooth muscle relaxation, vascular tone and receptor mapping in blood vessels.
Airway and pulmonary models
Experimental lung and airway models have examined VIP's signaling in airway smooth muscle, pulmonary vessels and neurogenic pathways.
How strong is the evidence?
| Research area | Typical study type | Evidence level |
|---|---|---|
| VPAC receptor binding and cAMP | Cell studies | Extensive, well established |
| Smooth muscle and vascular tone | Tissue and preclinical models | Substantial, model-dependent |
| Airway and pulmonary signaling | Tissue and preclinical models | Moderate |
| Neuro-immune and CNS signaling | Cell and preclinical models | Active, still developing |
Open questions remain. VIP is broken down quickly by enzymes in laboratory settings, which complicates experiments. It also acts on several receptors and tissues at once, so separating one effect from another is hard. Results in a cell line do not automatically carry over to intact tissue.
How does VIP compare with related peptides?
VIP sits in a family of similar-sized peptides with different receptor targets.
| Peptide | Length | Main receptors |
|---|---|---|
| VIP | 28 | VPAC1, VPAC2 |
| PACAP-38 | 38 | PAC1, VPAC1, VPAC2 |
| Secretin | 27 | Secretin receptor |
| Glucagon | 29 | Glucagon receptor |
PACAP is the closest relative because it shares both VPAC receptors with VIP. It also has its own PAC1 receptor, which VIP does not bind strongly.
What is in the VIP 10mg vial?
Our Vasoactive Intestinal Peptide (VIP) | 10mg is a synthetic form of the natural 28-residue peptide. The product page lists these identifiers:
- CAS number: 37221-79-7
- Molecular formula: C₁₄₇H₂₃₈N₄₄O₄₂S
- Molecular weight: about 3326.8 g/mol
- Length: 28 amino acids
Our peptides are synthesized at a WHO/GMP and ISO 9001 certified laboratory in California. The product is supplied strictly for in vitro and preclinical research.
How is VIP tested?
Identity is confirmed by mass spectrometry, and purity by HPLC. The measured mass should match the molecular weight above. VIP contains one methionine, an amino acid that oxidizes easily. Oxidation adds about 16 daltons, so a good report should show no significant peak at that shift.
The Certificate of Analysis for this product shows these results for the lot. For a walk-through of each line, see our line-by-line COA guide. For why mass and purity answer different questions, see our TB-500 testing article.
Frequently asked questions
What does VIP stand for?
VIP stands for vasoactive intestinal peptide. Some papers write it as vasoactive intestinal polypeptide.
Is VIP the same as PACAP?
No. They are different peptides that share the VPAC1 and VPAC2 receptors. PACAP also acts on a third receptor, PAC1.
Why do VIP studies often mention a short half-life?
Published work reports that VIP is degraded quickly by peptidases, which are enzymes that cut peptides. Researchers must account for this when designing experiments.
Is VIP only found in the gut?
No. Despite the name, it is also expressed in the nervous system, airways and immune-associated tissues.
What is the CAS number for VIP?
The CAS number listed for our VIP product is 37221-79-7. Check it against the Certificate of Analysis for your lot.
Does the 10mg vial contain 10mg of VIP exactly?
The label states the nominal amount. Content per vial is a separate testing question from purity, so check what the Certificate of Analysis reports. Our peptide research glossary explains the terms.
Every lot we sell has a Certificate of Analysis you can read before you order. Questions before you buy? Our team is in Chandler, Arizona: (888) 745-1505 or our contact page.
View Vasoactive Intestinal Peptide (VIP) | 10mgAll products sold by BioPure Peptides are intended strictly for in-vitro laboratory and research use only. They are not for human or animal consumption. These statements have not been evaluated by the U.S. Food and Drug Administration, and these products are not intended to diagnose, treat, cure, or prevent any disease.