Description
VIP (Vasoactive Intestinal Peptide) is a 28-amino-acid neuropeptide originally isolated from the intestine but expressed in tissue-spanning distribution throughout the body. Structurally, VIP belongs to the secretin-glucagon family and shows sequence homology to PACAP (Pituitary Adenylate Cyclase-Activating Polypeptide). In research literature, VIP is established as a multi-function peptide with effects on immune modulation, vascular function and neuroendocrine axes.
The research mechanism lies in the activation of VPAC1 and VPAC2 receptors, which are G-protein coupled and trigger intracellular cascades through cAMP signaling. In preclinical studies, VIP has been associated with anti-inflammatory effects, vasodilation, modulation of T-regulatory cells and neurotrophic properties. This multi-modality makes VIP a complex but mechanistically well-characterized research tool.
In animal models, VIP has been extensively characterized in inflammation models, vascular research setups and neurodegenerative studies. A particularity: VIP shows effects on Th1/Th2 balance in preclinical models and can contribute to a Th2 shift in autoimmune research models.
The half-life of native VIP is very short (a few minutes), making systemic research application challenging. In modern setups, stabilized VIP analogs or local application routes are frequently used.
VIP is available in 5mg vials as 10-vial packs.
This information is for research and educational purposes only. No medical recommendations.
Risks & Safety
VIP is described as largely well tolerated per study reports, but through its vasoactive action it has its own profile of effects to consider.
Observed in research and user reports:
- Circulation: VIP is a potent vasodilator. The literature describes flushing, warmth, low blood pressure or dizziness as circulation-related effects.
- Injection site: mild redness or pressure at the injection site is the most common local observation.
- Immune modulation: VIP modulates Th1/Th2 balance in preclinical models and can contribute to a Th2 shift, an active intervention in immune regulation.
- Very short half-life: native VIP has a duration of action of only a few minutes, which makes systemic use difficult to control.
- No long-term data: the characterization comes predominantly from preclinical models. Robust long-term human data do not exist.
This classification does not replace medical advice. Risk and responsibility for any actual use lie entirely with the buyer.
Studies
- Polypeptide with broad biological activity: isolation from small intestine - Science 1970: First description: isolation of a 28-amino-acid polypeptide from hog small intestine with potent vasodilatory and hypotensive action.
- The significance of vasoactive intestinal peptide in immunomodulation - Pharmacological Reviews 2004: Review of the role of VIP in the immune system: from a vasodilator hormone to a modulator of immune function with features of a type 2 cytokine.
- Pharmacology and functions of receptors for vasoactive intestinal peptide and pituitary adenylate cyclase-activating polypeptide: IUPHAR review 1 - British Journal of Pharmacology 2012: IUPHAR review of the receptors: VIP acts through the class B GPCRs VPAC1 and VPAC2, which also bind PACAP, with roles in circadian rhythms, immunity and inflammation and insulin secretion, among others.
- Vasoactive intestinal peptide: a neuropeptide with pleiotropic immune functions - Amino Acids 2013: More recent review: VIP is released by neurons and immune cells and acts as a neurotransmitter, immune regulator, vasodilator and secretagogue, with a focus on inflammatory and autoimmune disorders.
