High-purity Vasoactive Intestinal Peptide (VIP) is available for purchase as a reference-standard research compound intended exclusively for in vitro and preclinical laboratory experimentation. PX1 Research supplies USA-manufactured VIP featuring rigorous lot-specific analytical documentation, including reverse-phase HPLC and mass spectrometry verification, ensuring maximum stability and reproducibility across cellular and animal research models.
High-purity Vasoactive Intestinal Peptide (VIP) is available for purchase as a reference-standard research compound intended exclusively for in vitro and preclinical laboratory experimentation. PX1 Research supplies USA-manufactured VIP featuring rigorous lot-specific analytical documentation, including reverse-phase HPLC and mass spectrometry verification, ensuring maximum stability and reproducibility across cellular and animal research models.
Vasoactive Intestinal Peptide (VIP) is a fundamental 28-amino acid neuropeptide belonging to the glucagon/secretin superfamily of regulatory peptides. Initially identified in the mammalian gastrointestinal tract, VIP acts as a major non-adrenergic, non-cholinergic neurotransmitter and immunomodulatory signal across the central and peripheral nervous systems. Researchers seeking a verified supplier when sourcing VIP peptide for sale require stringently documented compounds to ensure experimental validity across cell culture assays and animal models.
In physiological research, VIP demonstrates broad regulatory activity, modulating vascular tone, epithelial electrolyte secretion, immune cell differentiation, and circadian pacemaking. Because structural degradation or sequence impurities can skew receptor affinity and intracellular signaling kinetics, acquiring high-purity material backed by comprehensive analytical verification is critical. PX1 Research provides institutional laboratories with reference-grade VIP, synthesized under strict quality controls to support reproducible empirical research.
The primary sequence of Vasoactive Intestinal Peptide consists of 28 amino acids (H-His-Ser-Asp-Ala-Val-Phe-Thr-Asp-Asn-Tyr-Thr-Arg-Leu-Arg-Lys-Gln-Met-Ala-Val-Lys-Lys-Tyr-Leu-Asn-Ser-Ile-Leu-Asn-NH2) with a C-terminal carboxamide modification essential for receptor activation. VIP exerts its biological actions primarily through interaction with two high-affinity Class B G-protein-coupled receptors: VPAC1 and VPAC2. It also binds with lower affinity to the PAC1 receptor, which is predominantly activated by pituitary adenylate cyclase-activating polypeptide.
Upon ligand binding to VPAC1 or VPAC2, the receptor couples to Gs proteins, activating adenylate cyclase and inducing a rapid elevation of intracellular cyclic adenosine monophosphate (cAMP). This cascade recruits protein kinase A (PKA) and downstream transcription factors such as CREB (cAMP response element-binding protein). In specific cell lineages, VIP receptor engagement also activates Gq/11 pathways, triggering phospholipase C activation and intracellular calcium mobilization. Investigators studying these pathways rely on detailed target profiling documented in our peptide research library to design controlled receptor-ligand interaction assays.
In preclinical immunology research, VIP is widely investigated as an endogenous anti-inflammatory agent. Rodent models of septic shock, inflammatory bowel disease, and rheumatoid arthritis have demonstrated that VIP administration suppresses the production of pro-inflammatory cytokines, including TNF-alpha, IL-6, IL-12, and IFN-gamma, primarily through the downregulation of nuclear factor kappa B (NF-kB) activation in macrophages and dendritic cells.
Simultaneously, VIP promotes the differentiation and survival of CD4+CD25+Foxp3+ regulatory T cells (Tregs) while inhibiting Th1 and Th17 inflammatory responses. In vitro assays using primary murine and human mononuclear cells indicate that VIP shifts the cytokine profile toward an anti-inflammatory phenotype characterized by elevated IL-10 and TGF-beta secretion. These properties make VIP a target of significant interest for research into immune homeostasis, mucosal barrier integrity, and transplantation tolerance models.
Beyond its peripheral immune effects, VIP plays a central role in neurobiology. Within the suprachiasmatic nucleus (SCN) of the hypothalamus—the master circadian pacemaker in mammals—VIP expressing neurons are crucial for synchronizing individual neuronal oscillations to environmental light-dark cycles. Preclinical knock-out models lacking VIP or VPAC2 exhibit disrupted circadian rhythms, altered behavioral periodicity, and compromised clock gene expression (such as Per1 and Cry1).
Furthermore, in vitro and animal models of neurodegeneration have shown that VIP exerts potent neuroprotective effects against glutamate excitotoxicity, oxidative stress, and microglial-mediated neuroinflammation. By stimulating astrocytes to release activity-dependent neuroprotective protein (ADNP) and neurotrophic factors, VIP preserves neuronal viability in rodent models of Parkinson's disease, Alzheimer's pathology, and ischemic stroke. Laboratories evaluating neuroinflammatory pathways can review comparative compound data in our research library hub.
Vasoactive Intestinal Peptide shares substantial sequence homology and structural domain architecture with several other peptide hormones within the secretin family. Understanding the subtle functional divergences between these homologous peptides is vital for experimental design when selecting selective agonists or antagonists for receptor mapping.
When comparing VIP to related signaling molecules, PACAP research compounds exhibit dual affinity for VPAC1 and VPAC2, but display a 100-fold higher affinity for the PAC1 receptor compared to VIP. Similarly, Secretin peptide mechanisms focus predominantly on pancreatic and biliary bicarbonate secretion via dedicated secretin receptors, whereas GHRH research peptides act primarily on somatotropes in the anterior pituitary. High-resolution binding assays and structural modeling rely on cross-referencing these homologous structures to eliminate cross-reactivity artifacts in cellular signaling studies.
To maintain the structural integrity and biological activity of synthetic VIP peptide, strict handling protocols must be observed upon receipt. Lyophilized VIP should be stored at -20°C or -80°C in a desiccated environment, shielded from light. Under these conditions, the desiccated powder remains stable for extended periods, minimizing spontaneous oxidation of the methionine residue at position 17.
Reconstitution should be performed using sterile, cold reconstituting media, such as 0.1% acetic acid or sterile cell-culture grade water, depending on the requirements of the assay. Once reconstituted, the solution can be diluted into sterile phosphate-buffered saline (PBS) or culture media containing carrier proteins (such as 0.1% BSA) to prevent non-specific adsorption to polypropylene microcentrifuge tubes. Repeated freeze-thaw cycles must be avoided by aliquoting the reconstituted solution into single-use working volumes prior to deep-freeze storage at -80°C.
When procuring VIP peptide for sale, researchers must ensure that the supplier provides rigorous, lot-specific quality assurance documentation. Standard commercial peptide synthesis can introduce truncated sequences, deletion peptides, or residual chemical reagents (such as TFA salts, piperidine, or organic solvents) if purification and post-processing steps are inadequate.
PX1 Research enforces comprehensive quality standards for every lot of VIP supplied:
• Reverse-Phase HPLC (RP-HPLC): Establishes chemical purity exceeding 98%, confirming the absence of closely eluting synthesis side-products or failure sequences.
• Electrospray Ionization Mass Spectrometry (ESI-MS): Verifies exact molecular mass (theoretical MW: 3326.8 Da), confirming accurate primary amino acid composition.
• Endotoxin Testing: Quantifies lipopolysaccharide contamination via Chromogenic LAL assay to guarantee level safety (<0.01 EU/mg) for sensitive cell culture and in vivo models.
• Domestic Synthesis & Quality Control: Manufactured in the USA within state-of-the-art facilities compliant with current Good Manufacturing Practices (cGMP) guidelines and verified by an ISO 17025 accredited analytical lab.
Principal investigators managing high-throughput laboratories can access detailed sourcing parameters through our wholesale lab portal.
In immunological and cell culture research, bacterial endotoxins (LPS) represent a major confounding variable. Exogenous endotoxins introduce false-positive signals in macrophage activation assays, trigger non-specific toll-like receptor 4 (TLR4) signaling, and induce premature cell death in primary culture systems.
Standard laboratory reagents that lack certified endotoxin limits risk compromising months of experimental work. PX1 Research subjects all VIP lots to stringent Limulus Amebocyte Lysate (LAL) testing, ensuring that background endotoxin levels remain far below regulatory and scientific threshold limits. This guarantees that observed physiological changes in cytokines, cyclic AMP generation, or transcriptomic profiles can be attributed exclusively to VIP receptor signaling.
Securing consistent, high-purity VIP peptide is essential for long-term research programs requiring multi-lot comparability. Variations in peptide content, counter-ion composition, or hydration state between batches can introduce batch-to-batch variability in cellular responsiveness and pharmacodynamic modeling.
PX1 Research provides fully documented Certificate of Analysis (COA) files with every order, detailing exact chromatographic purity, mass spectrum analysis, net peptide content, and endotoxin metrics. Laboratories purchasing VIP for ongoing projects benefit from transparent lot tracking and domestic inventory shipping direct from our California and Arizona logistics facilities. Explore our complete range of reference compounds across our research peptides selection.
What is the certified purity level of VIP peptide from PX1 Research?
Every lot of VIP peptide supplied by PX1 Research is verified via Reverse-Phase HPLC to possess a chemical purity of >98%. Detailed mass spectrum (ESI-MS) analysis is conducted to confirm sequence integrity and correct molecular weight.
How should VIP peptide be reconstituted for laboratory assays?
VIP should be reconstituted using sterile, cold 0.1% acetic acid or sterile cell-culture grade water depending on assay specifications. To prevent peptide adherence to container walls, sterile PBS containing 0.1% bovine serum albumin (BSA) or human serum albumin (HSA) can be used for secondary dilutions.
What receptors does Vasoactive Intestinal Peptide target?
VIP acts as a high-affinity agonist at VPAC1 and VPAC2 G-protein-coupled receptors. It also displays weak cross-reactivity with the PAC1 receptor, stimulating adenylate cyclase and increasing intracellular cAMP levels upon binding.
Is VIP peptide tested for endotoxin content?
Yes. PX1 Research subjects every lot of VIP peptide to quantitative Chromogenic Limulus Amebocyte Lysate (LAL) testing to ensure endotoxin levels remain below strictly controlled research standards (<0.01 EU/mg), preventing cellular toxicity or artifactual immune activation.
How does VIP differ functionally from PACAP in research applications?
While VIP and PACAP share high affinity for VPAC1 and VPAC2 receptors, PACAP exhibits significantly higher selective affinity (over 100-fold) for the PAC1 receptor compared to VIP. This differential receptor selective profile allows researchers to dissect distinct signaling cascades in neuroendocrine and vascular tissue models.
What are the recommended storage conditions for lyophilized VIP?
Lyophilized VIP should be stored at -20°C or -80°C in a dry container with desiccant, protected from direct light. Stored properly under these conditions, the dry peptide remains stable for up to 24 months without significant degradation.
Are PX1 Research peptides synthesized domestically?
Yes. All research peptides from PX1 Research are synthesized in USA-based, GMP-compliant facilities and independently verified by ISO 17025 accredited testing laboratories.
All products are sold strictly for laboratory and research use only. Not for human or veterinary use, diagnosis, treatment or consumption. Statements have not been evaluated by the FDA.