For broader research context on nootropic compounds, including comparative stacks, cycling considerations, and interaction notes, see the Complete Nootropic Cheat Sheet.
What Is VIP?
Vasoactive Intestinal Peptide (VIP) is a 28-amino-acid neuropeptide and peptide hormone expressed throughout the gastrointestinal tract, lungs, central and peripheral nervous systems, and immune cells. Despite its name (reflecting its discovery context — relaxation of intestinal smooth muscle via vasodilation), VIP has since been recognized as one of the most pleiotropic signaling peptides known, with roles in immune regulation, circadian rhythm, neuroprotection, and bronchopulmonary function.
Anti-inflammatory Mechanisms
VIP is a potent endogenous anti-inflammatory signal, inhibiting production of TNF-α, IL-6, IL-12, and nitric oxide in activated macrophages and monocytes through VPAC receptor activation and downstream cAMP/PKA signaling. It promotes regulatory T-cell generation while suppressing Th1 and Th17 inflammatory responses — making VIP research highly relevant for autoimmune and inflammatory conditions.
Pulmonary and Circadian Applications
VIP receptors are among the most abundantly expressed in lung tissue, where VIP produces bronchodilation, inhibits mast cell degranulation, and protects against pulmonary hypertension. Inhaled VIP has been studied for pulmonary arterial hypertension with significant hemodynamic improvements in Phase 2 trials. VIP neurons in the suprachiasmatic nucleus (SCN) are also critical for circadian clock synchronization — coordinating the phase of individual SCN neurons into a coherent population rhythm — positioning VIP at the intersection of immune, pulmonary, and chronobiological research.
Quick Reference
Member reference tables summarize the compound's research parameters.
Research Indications
Research Protocols
As reported in cited literature and research-community logs (see Research Citations below), not a personal dosing recommendation.
This member section describes parameters reported in the research literature.
Peptide Interactions
This member section summarizes reported compound interactions and evidence limitations.
Reported Research Time Points
This member section summarizes reported research time points.
Safety Notes
Included for harm-reduction awareness only, in the event this compound is encountered outside its labeled research use. Inclusion here does not imply RUO Codes endorses, recommends, or instructs human use.
This member section discusses research safety considerations and uncertainties.
Quality Indicators
Research Citations
- Pharmacology and functions of receptors for vasoactive intestinal peptide and pituitary adenylate cyclase-activating polypeptide: IUPHAR review 1
Harmar AJ, Fahrenkrug J, Gozes I, Laburthe M, May V, Pisegna JR, et al., 2012, British Journal of Pharmacology - The Use of IV Vasoactive Intestinal Peptide (Aviptadil) in Patients With Critical COVID-19 Respiratory Failure: Results of a 60-Day Randomized Controlled Trial
Youssef JG, Lavin P, Engelen MPKJ, et al., 2022, Critical Care Medicine - Vasoactive intestinal polypeptide (VIP) corrects chronic inflammatory response syndrome (CIRS) acquired following exposure to water-damaged buildings
Shoemaker RC, House D, Ryan JC, 2013, Health - Vasoactive intestinal peptide prevents experimental arthritis by downregulating both autoimmune and inflammatory components of the disease
Delgado M, Abad C, Martinez C, Leceta J, Gomariz RP, 2001, Nature Medicine - Vasoactive intestinal peptide as a new drug for treatment of primary pulmonary hypertension
Petkov V, Mosgoeller W, Ziesche R, et al., 2003, Journal of Clinical Investigation - From vasoactive intestinal peptide (VIP) through activity-dependent neuroprotective protein (ADNP) to NAP: a view of neuroprotection and cell division
Gozes I, Divinski I, Pilzer I, et al., 2003, Journal of Molecular Neuroscience - Editorial: vasoactive intestinal peptide (vip): historic perspective and future potential
Foster N, 2012, Endocr Metab Immune Disord Drug Targets - A structure-function study of PACAP using conformationally restricted analogs: Identification of PAC1 receptor-selective PACAP agonists
Ramos-Álvarez I, Mantey SA, Nakamura T, 2015, Peptides - From vasoactive intestinal peptide (VIP) through activity-dependent neuroprotective protein (ADNP) to NAP: a view of neuroprotection and cell division
Gozes I, Divinsky I, Pilzer I, 2003, J Mol Neurosci - Vasoactive intestinal peptide: cardiovascular effects
Henning RJ, Sawmiller DR, 2001, Cardiovasc Res - VIP -- a 'very important peptide' in the sympathetic nervous system?
Klimaschewski L, 1997, Anat Embryol (Berl)