Sweden was the birthplace of the fascinating peptide vasoactive intestinal peptide (VIP), which was found to function as a hormone in the digestive tract. It is structurally and functionally similar to other crucial peptides like secretin, glucagon, and gastric inhibitory peptides. The development of modern biotechnology has enabled researchers to determine the full VIP amino acid sequence and analyze its structural and functional relationship to other peptides.

After being thought to be limited to the digestive tract, VIP was later discovered in the brain and other parts of the nervous system. But because of its rarity and complicated functions, VIP research has moved at a staggering pace so far.

Major advances in VIP study over the past few years have increased our knowledge of the compound’s potential uses and physiological functions. Scientists have developed antibodies targeting VIP, allowing for precise localization of the protein throughout the brain.

While previous studies mainly focused on mapping VIP distribution in the central nervous system, recent efforts have been dedicated to unraveling its physiological functions. This review aims to explore the emerging data on the possible roles of VIP in CNS and pituitary functions.  [R]

In the following sections, we will understand VIP on research, exploring its effects, mechanisms, and potential applications as a research chemical. It is important to note that VIP is not promoted for human use but instead serves as a valuable tool for scientific exploration and discovery.

Key Features of VIP

RCD.Bio offers VIP with the following specifications:

  • A purity of 98%, verified by third-party laboratory testing.
  • Available in Peptide Form: 10mg
  • VIP[R]
    • CAS Number: 37221-79-7
    • Molecular weight: 3326.8 g/mol
    • Chemical Formula: C147H237N43O43S
    • IUPAC Name: (2S)-4-amino-2-[[(2S)-2-[[(2S,3S)-2-[[(2S)-2-[[(2S)-4-amino-2-[[(2S)-2-[[(2S)-2-[[(2S)-6-amino-2-[[(2S)-6-amino-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-5-amino-2-[[(2S)-6-amino-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S,3R)-2-[[(2S)-2-[[(2S)-4-amino-2-[[(2S)-2-[[(2S,3R)-2[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-[[(2S)-2-amino-3-(1H-imidazol-4-yl)propanoyl]amino]-3=hydroxypropanoyl]amino]-3carboxypropanoyl]amino]propanoyl]amino]-3methylbutanoyl]amino]-3-phenylpropanoyl]amino]-3-hydroxybutanoyl]amino]-3-carboxypropanoyl]amino]-4oxobutanoyl]amino]-3-(4-hydroxyphenyl)propanoyl]amino]-3-hydroxybutanoyl]amino]-5 carbamimidamidopentanoyl]amino]-4-methylpentanoyl]amino]-5 carbamimidamidopentanoyl]amino]hexanoyl]amino]-5oxopentanoyl]amino]-4methylsulfanylbutanoyl]amino]propanoyl]amino]-3methylbutanoyl]aminohexanoyl]amino]hexanoyl]amino]-3-(4-hydroxyphenyl)propanoyl]amino]-4methylpentanoyl]amino]-4-oxobutanoyl]amino]-3hydroxypropanoyl]amino]-3 methylpentanoyl] amino] -4-methylpentanoyl]amino]-4-oxobutanoic acid

How VIP Works

Vasoactive intestinal peptide (VIP) is a versatile molecule that is not only widely expressed and secreted in immune and endocrine cells but also in both the central and peripheral nervous systems. This multifunctional neuropeptide exerts a diverse range of biological effects and serves as a neurotransmitter, neurotrophic factor, and neuroprotective factor within the central nervous system (CNS). The neuroprotective properties of VIP are believed to be mediated through both direct and indirect mechanisms.

In the direct mechanism, cyclic adenosine monophosphate (cAMP) has been identified as a key signaling molecule responsible for the neuroprotective effects of VIP. Activation of VIP receptors triggers intracellular signaling pathways that lead to the elevation of cAMP levels. Increased cAMP, in turn, initiates a cascade of events that promote cell survival and protect against neurodegenerative processes. This direct neuroprotective action of VIP mediated by cAMP signaling has been well-documented in various experimental models.

On the other hand, the indirect neuroprotective effects of VIP involve the interaction with astrocyte cells in the CNS. Astrocytes, a type of glial cell, play a crucial role in supporting neuronal function and maintaining the health of the nervous system. Studies have shown that VIP can modulate astrocyte activity and promote their neuroprotective functions. The indirect neuroprotective effects of VIP mediated by astrocytes do not rely on cAMP formation, indicating the involvement of distinct signaling pathways.[R]

The scientific basis behind the benefits of VIP

Numerous research investigations and trials on animals suggest that VIP  may have several benefits. 

VIP and Inflammatory Bowel Disease

A study demonstrates the potential therapeutic benefit of vasoactive intestinal peptide (VIP) delivered in the form of sterically stabilized micelles (VIP-SSM) in the treatment of inflammatory bowel disease (IBD), specifically ulcerative colitis.

In their experiments using a mouse model of colitis induced by dextran sulfate sodium (DSS), the researchers compared the effectiveness of VIP administered on alternate days with VIP-SSM and the free peptide. They found that both VIP-SSM and VIP, when administered on alternate days, were capable of alleviating colitis in mice. However, when given as a single dose in a therapeutic setting, VIP-SSM showed superior benefits compared to the free peptide. [R] Further research and clinical studies are necessary to validate these findings and assess the safety and efficacy of VIP-SSM in human patients with Inflammatory Bowel Diseases.

VIP and Parkinson’s Disease

Parkinson’s disease (PD) is a common brain disorder where certain nerve cells in the brain die, leading to problems with movement. Scientists have been studying a toxin called MPTP to better understand PD and find ways to treat it. They discovered that special cells in the brain called microglia become activated and release harmful substances, contributing to the disease. Current treatments for PD are not very effective, so researchers have been looking for ways to stop the harmful actions of these activated microglia.

One molecule of interest is called vasoactive intestinal peptide (VIP). VIP is a natural substance in the body that has strong anti-inflammatory effects, meaning it can reduce harmful inflammation in the brain. In this study, researchers wanted to see if VIP could protect against PD in the MPTP model.

The results were promising. When VIP was given to the mice in the study, it helped protect the brain cells that are usually damaged in PD. It reduced the loss of important nerve cells and prevented the harmful activation of microglia. VIP also decreased the production of toxic substances released by these activated cells.

These findings suggest that VIP could be a valuable treatment option for PD and other brain diseases associated with cognitive function where inflammation plays a role. By reducing inflammation and stopping the harmful actions of activated microglia, VIP shows the potential to protect the brain from damage. Further research is needed to fully understand how VIP works and its potential as a therapy for PD.[R]

VIP and Erectile Dysfunction

Vasoactive intestinal peptide (VIP) is a substance found in the body that helps regulate various functions. Recent research has shown that VIP is important for erectile function in men. A study involving impotent men found that those with more severe erectile dysfunction had lower levels of VIP in their penises. On the other hand, men with some remaining erectile function had more variable VIP levels. This suggests that VIP plays a key role in penile health and may contribute to the development of erectile dysfunction.

In the study, researchers examined the penises of impotent men and found that the depletion of VIP-containing nerves was closely linked to the severity of erectile dysfunction. This means that the more VIP nerves were depleted, the worse the erectile dysfunction. The study also compared the penises of impotent diabetics with those of healthy individuals and found that VIP levels were significantly lower in the diabetic group. This supports the idea that VIP is an important neurotransmitter for penile erection and that its depletion may contribute to erectile dysfunction, especially in diabetic individuals.[R]

Although the changes observed in the penises of impotent men through conventional histology were mild, measuring VIP levels revealed a substantial depletion in VIP levels, particularly in diabetic individuals with erectile dysfunction. This suggests that the reduction in VIP may be a crucial factor in the development of erectile dysfunction.  Further research is needed to explore therapeutic strategies aimed at restoring VIP levels and potentially improving erectile function in men affected by this distressing condition.

VIP and Female sexual arousal and vaginal lubrication

The human vagina is known to have a dense network of vasoactive intestinal polypeptide (VIP) immunoreactive nerve fibers. This study examines the impact of VIP on vaginal lubrication and blood flow in normal, non-pregnant women. The effects of intravenous VIP infusion on vaginal blood flow and lubrication were measured, alongside monitoring arterial blood pressure, pulse frequency, and VIP concentration in peripheral blood.

The study involved fourteen normal non-pregnant women, and they received an intravenous infusion of VIP at a median concentration of 200-300 pmol/l for 30 minutes. Measurements were taken to assess vaginal blood flow using the heat clearance technique, and vaginal lubrication was quantified by the weight gain of pre-weighed filter papers placed on the vaginal wall for 30 minutes. The results demonstrated that VIP infusion led to a significant increase in vaginal blood flow and a 100% increase in vaginal lubrication. Vaginal blood flow increased, indicating a dilation of blood vessels in the vaginal area. This vasodilation is believed to play a crucial role in enhancing genital responsiveness during sexual arousal. The increase in vaginal lubrication observed after VIP infusion suggests that VIP may contribute to the natural lubrication process, facilitating a more comfortable and pleasurable sexual experience. [R]

These findings suggest that VIP may play a role in the local physiological changes observed during sexual arousal, including genital vasodilation and increased vaginal lubrication. Further research is needed to explore the precise mechanisms by which VIP influences these processes and to determine its potential therapeutic implications for individuals experiencing difficulties with sexual arousal and vaginal lubrication.

Vasoactive Intestinal Peptide and Cardiac Fibrosis

Myocardial fibrosis can impair the heart’s ability to contract properly and can lead to complications such as reduced cardiac function, heart failure, and arrhythmias. A study investigated whether a decrease in vasoactive intestinal peptide (VIP) levels in the heart is associated with early myocardial fibrosis. The study conducted experiments using spontaneously hypertensive rats (SHRs) and normotensive control rats (WKYs) assigned to different sodium diets. They monitored blood pressure and collected samples to measure plasma VIP concentration and examine the hearts for histology and VIP concentration.

The results showed that the degree of myocardial fibrosis increased with higher dietary sodium intake in both WKYs and SHRs. Additionally, myocardial VIP concentration decreased with increasing dietary sodium intake in both groups. There was a negative correlation between VIP concentration and the extent of myocardial fibrosis in both WKYs and SHRs. Based on these findings, the study suggests that depletion of VIP in the heart may play a role in the development of myocardial fibrosis, particularly in response to increased dietary sodium intake. [R] The study doesn’t show any significant result in lower arterial blood pressure.

More study is needed to fully understand the therapeutic potential of VIP and its fibrotic pathways in a variety of inflammatory diseases such as cardiac fibrosis, pulmonary fibrosis, or lung disease.

VIP in Appetite, Feeding Behavior, and Body Mass Composition

VIP is abundantly expressed in both the central and peripheral nervous systems, as well as in the gastrointestinal tract, where it serves various physiological functions. Some studies have reported that VIP centrally regulates feeding behavior in different vertebrate species, including goldfish, chickens, and rodents.  The aim of this study was to shed light on the physiological pathways through which VIP influences appetite, satiety, feeding behavior, metabolic hormones, and body mass composition. To achieve this, the researchers compared VIP-deficient (VIP −/−) mice with age-matched wild-type (WT) littermates. The results of the study revealed that the genetic absence of VIP led to significant reductions in body weight and fat mass, while lean mass increased as the mice aged. Additionally, the VIP−/− mice exhibited disrupted patterns of circadian feeding behavior, resulting in the absence of regular nocturnal/diurnal feeding cycles. These changes were associated with altered secretion of adiponectin, GLP-1, leptin, PYY, and insulin in the VIP−/− mice. Based on these findings, it can be concluded that endogenous VIP plays a crucial role in the control of appetite, satiety, feeding behavior, body mass composition, and the secretion of key metabolic hormones (such as prolactin secretion and gastric acid secretion) . VIP is instrumental in regulating body phenotype by significantly influencing body weight and fat mass accumulation. Therefore, VIP signaling emerges as a critical factor in modulating appetite, satiety, and body mass phenotype, making it a potential target for future treatments of obesity.[R]

Further research is necessary to delve deeper into the underlying mechanisms by which VIP exerts its effects on appetite regulation and metabolic hormone secretion


The information presented here is for educational purposes only and should not be construed as medical advice. VIP is intended for laboratory research use only and is not intended for human consumption.

Potential side effects

While vasoactive intestinal peptide (VIP) offers potential therapeutic benefits, it is important to consider the potential side effects associated with its use. A study assessing the side effects of VIP administration revealed several notable effects. Among the reported side effects, the most common were migraine attacks, nausea, photophobia (sensitivity to light), phonophobia (sensitivity to sound), flushing (redness and warmth of the skin), warm sensations, and heart palpitations. These side effects were reported by a significant percentage of participants, indicating the potential discomfort that can arise from VIP administration. [R]

Where Can I Buy VIP Online? offers VIP for laboratory and research use only.

When buying  VIP, it is important to choose a reputable seller who provides quality  VIP. At, each product is accompanied by a third-party-issued Certificate of Analysis showing the identification, purity, and concentration of our product.


Vasoactive Intestinal Peptide (VIP), is a peptide with various functions in the body. Initially discovered in the digestive tract, VIP has also been found in the brain and nervous system. Recent research has focused on understanding its physiological functions and potential applications. VIP works through direct mechanisms, involving cyclic adenosine monophosphate (cAMP) signaling for neuroprotection, and indirect mechanisms, involving interactions with astrocytes. Studies have explored VIP’s effects on Parkinson’s disease, erectile dysfunction, female sexual arousal, inflammation-related conditions, and corneal infection. VIP has shown promising results as potent anti-inflammatory effects, protecting brain cells, improving erectile function, enhancing vaginal lubrication, and modulating immune system responses. However, further research is needed to fully understand VIP’s mechanisms and potential therapeutic applications. Several studies have also shown its effect on smooth muscle relaxation, intestinal barrier homeostasis, and multiple sclerosis.


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