VIP (Vasoactive Intestinal Peptide)
Extensively StudiedNeuropeptide
Vasoactive Intestinal Peptide (VIP) is a 28-amino acid neuropeptide that has been studied in respiratory and vascular biology research. It has been investigated for its effects on smooth muscle relaxation, bronchodilation, and pulmonary vasodilation through VPAC receptor signaling. Published research has examined its distribution and physiological roles. RaysunPeptide supplies VIP for qualified research and laboratory applications.
Mechanism of Action
VIP binds to VPAC1 and VPAC2 G protein-coupled receptors, activating adenylyl cyclase and increasing intracellular cAMP and PKA activity. This triggers phosphorylation of CREB and other transcription factors. VIP causes vasodilation through NO-dependent and independent mechanisms, stimulates intestinal secretion, relaxes smooth muscle, inhibits gastric acid secretion, and has positive inotropic/chronotropic cardiac effects.
Key Benefits
Molecular Data
Dosing Protocols
| Goal | Dose | Frequency | Route |
|---|---|---|---|
| General use | 50-100 mcg | 1-2x daily | SubQ or IV |
| Research protocols | 100-200 mcg | As directed | SubQ or IV |
Research Indications
Cardiovascular
VIP inhalation shows striking efficacy with increased mixed venous oxygen saturation and exercise capacity.
Dilates peripheral blood vessels through NO-dependent mechanisms above 100 pmol doses.
Coronary vasodilation with positive inotropic and chronotropic effects on the heart.
Neurological
Promising therapeutic target for Alzheimer's, Parkinson's, and other neurological disorders.
Potential therapeutic target being researched for ASD.
Produced in suprachiasmatic nuclei; involved in circadian regulation.
Metabolic & Immune
Promotes insulin secretion in glucose-dependent manner via VPAC2; low hypoglycemia risk.
Potent anti-inflammatory effects useful in IBD and autoimmune conditions.
Therapeutic potential for pulmonary and systemic sarcoidosis.
Peptide Interactions
No known negative interactions; different mechanisms.
Both have immunomodulatory effects; may complement each other.
Both have anti-inflammatory properties.
What to Expect
Side Effects & Safety
Common (Generally Mild)
- •Vasodilation (flushing, warmth)
- •Hypotension
- •Increased heart rate
- •Gastrointestinal effects (diarrhea possible)
- •Headache
Stop Signs (Seek Medical Attention)
- ⚠Severe hypotension
- ⚠Allergic reaction symptoms
- ⚠Severe diarrhea
- ⚠Cardiac arrhythmias
Contraindications
- ✕Severe hypotension
- ✕VIPoma or related tumors
- ✕Pregnancy or breastfeeding
- ✕Severe cardiac conditions
Quality Checklist
Good Signs ✓
- White lyophilized powder
- Clear solution after reconstitution
- Intact vacuum seal
Warning Signs !
- Use quickly after reconstitution (unstable)
Bad Signs ✕
- Discolored powder
- Cloudy solution
- Particulates visible
References
VIP inhalation showed striking efficacy with increased mixed venous oxygen saturation and exercise capacity.
VIP promotes glucose-dependent insulin secretion via VPAC2, reducing hypoglycemia risk.
VIP and receptors are promising therapeutic targets for AD, PD, and autism spectrum disorders.
Comprehensive review of VIP receptor signaling and therapeutic applications.
FAQs
How effective is VIP for pulmonary hypertension and can it replace conventional treatments?
VIP inhalation showed striking efficacy with increased mixed venous oxygen saturation and exercise capacity in pulmonary hypertension patients. However, it's complementary to conventional therapy rather than a replacement - the very short 2-minute half-life requires frequent dosing, making it challenging for long-term use without newer stabilized analogs.
Does VIP cause dangerous hypotension or can it be used safely in most patients?
VIP's vasodilation can cause hypotension and flushing, especially at higher doses. Careful dose titration and patient monitoring are essential. Patients with baseline hypotension or severe cardiac conditions should avoid use, but mild transient vasodilation is manageable in most populations with proper medical supervision.
Why is VIP rarely used clinically if research shows such promise?
VIP's extremely short 1-2 minute half-life makes it impractical for routine clinical use - requiring constant infusions or multiple daily injections. Stabilized analogs (like stearyl-Nle17-VIP) are 100-fold more potent but rarely available outside research settings. Limited commercial development has restricted clinical availability despite strong research foundation.
Can VIP improve insulin secretion for diabetes without causing hypoglycemia?
Yes, VIP promotes glucose-dependent insulin secretion via VPAC2 receptors, meaning it only stimulates insulin when blood glucose is elevated. This glucose-dependent mechanism makes hypoglycemia risk very low compared to other insulin secretagogues, making VIP theoretically safer for diabetes support.
