VIP

Volume Pricing

Price per pack (10 vials). Discount applies to this compound only – no mix and match.

Vasoactive Intestinal Peptide (VIP) — Pleiotropic Neuropeptide Acting at VPAC1, VPAC2, and PAC1 Receptors

Vasoactive Intestinal Peptide (VIP) is a 28-amino acid neuropeptide first isolated from porcine duodenum by Sami Said and Viktor Mutt in 1970, initially characterized by its potent vasodilatory and smooth muscle-relaxant properties. Subsequent decades of research revealed VIP to be among the most widely distributed neuropeptides in the mammalian body, expressed in enteric neurons, central and peripheral nervous system, pulmonary tissue, and immune cells. VIP signals through three receptor subtypes: VPAC1 and VPAC2 (both Gs-coupled GPCRs that elevate cAMP) and PAC1R (also activated by PACAP, with lower VIP affinity). The peptide is now understood to be a critical regulator of circadian output — VIP is the primary neurotransmitter of the suprachiasmatic nucleus (SCN), the mammalian master clock, where it coordinates oscillator synchronization across SCN neurons. This functional breadth — spanning immunomodulation, smooth muscle regulation, circadian biology, and neuroprotection — makes VIP an unusually versatile research compound across multiple systems biology frameworks.

Why VIP’s Receptor Subtype Selectivity Matters

VPAC1 and VPAC2 share high sequence homology but show distinct tissue distribution and downstream signaling profiles that determine VIP’s context-dependent effects. VPAC1 is the dominant receptor in the lung, liver, and intestinal mucosa; VPAC2 predominates in the SCN, pancreatic islets, and immune compartments. At the immunological level, VPAC2 activation on regulatory T cells (Tregs) promotes their expansion and suppresses effector T cell activation — a mechanism under active investigation in autoimmunity and inflammatory bowel disease models. At the SCN, VPAC2 signaling is required for inter-neuronal synchronization of circadian oscillators; VPAC2-null mice display severely fragmented circadian rhythms. Understanding which receptor mediates a given VIP effect is essential for interpreting research outcomes across different tissue systems.

Research Applications

VIP is used in studies examining:

• Circadian biology — SCN oscillator synchronization and VPAC2-dependent clock entrainment
• Inflammatory bowel disease and intestinal mucosal immunity models
• Pulmonary arterial hypertension — VIP as endogenous pulmonary vasodilator
• Autoimmunity and Treg biology — VPAC2-mediated regulatory T cell expansion
• Neuroinflammation — VIP’s neuroprotective and anti-inflammatory actions in CNS models
• VPAC1 vs. VPAC2 receptor subtype pharmacology in comparative binding studies
• Pancreatic islet biology — VIP-mediated insulin secretion modulation

Specifications

Reconstitution

VIP arrives as lyophilized powder and must be reconstituted with bacteriostatic water prior to use. Use the formula:

Total mg ÷ Volume added (mL) = Concentration (mg/mL)

Example: 5mg vial + 1mL BAC water = 5mg/mL solution; 10mg vial + 2mL BAC water = 5mg/mL solution

Reconstituted peptide should be stored at 2–8°C and used within 28–30 days.

Protocol Notes

Research dosing for VIP spans a wide range depending on route and model system. Human infusion studies have characterized pharmacokinetics and receptor saturation; rodent subcutaneous models use weight-normalized doses. VIP’s short plasma half-life (approximately 1–2 minutes due to rapid peptidase cleavage) means infusion or repeated dosing protocols are typical in in vivo research.

• Dose range (human infusion literature): 25–200 pmol/kg/min IV infusion in published human pharmacology studies
• Dose range (rodent literature): 10–50 nmol/kg SC or IP in mechanistic mouse and rat studies
• Frequency: Continuous infusion or repeated daily dosing in most in vivo models; single-dose bolus in receptor characterization studies
• Study duration: Acute studies (single dose) to 4-week repeated-dose protocols in rodent models

Research Stacks

VIP is commonly paired in research settings with:

• Cerebrolysin — Cerebrolysin delivers low-molecular-weight neurotrophic peptide fragments with NGF- and BDNF-like activity; pairing with VIP’s VPAC1/VPAC2-mediated neuroprotective, anti-inflammatory, and cAMP-inducing signaling provides a model for studying multi-pathway neuronal survival support.
• Semax — Semax upregulates BDNF and engages melanocortin receptors to support neuroplasticity and cortical activation; combined with VIP’s vasodilatory, anti-inflammatory, and VPAC receptor-mediated neuroprotective properties, the pairing is used in models examining convergent CNS support mechanisms.
• Selank — Selank inhibits enkephalin-degrading enzymes and modulates GABAergic tone for anxiolytic effects; pairing with VIP’s broad neuroimmune regulatory activity (including effects on mast cells and Treg polarization) is studied in models of neuroinflammation and stress-related immune activation.

Purity Guarantee

Every batch is ≥99% purity. If you independently test your compound and the results don’t match — send us the COA and we’ll issue store credit, no questions asked.