Lab Reference Library / VIP (Vasoactive Intestinal Polypeptide)
Detox, Mold & CIRS
VIP (Vasoactive Intestinal Polypeptide)
VIP · Vasoactive Intestinal Polypeptide · Vasointestinal PeptideReference range, optimal functional medicine levels, and why VIP is the master regulatory neuropeptide of the CIRS treatment protocol, how low VIP produces pulmonary arterial hypertension, circadian disruption, and persistent inflammation, and why VIP nasal spray must be the last step after upstream markers are normalized.
CIRS Final RegulatorPulmonary and Immune
Low CIRSBelow 23 pg/mL
Reference23 to 63 pg/mL
Optimal50 to 63 pg/mL
Unitspg/mL
← Back to Lab Reference Library
Category: Detox, Mold & CIRS | Also known as: Vasoactive Intestinal Polypeptide, Vasointestinal Peptide, VIP
1. What This Test Measures
VIP (vasoactive intestinal polypeptide) is a 28-amino acid neuropeptide belonging to the glucagon/secretin superfamily, produced by neurons throughout the enteric nervous system, the central and peripheral nervous systems, and the lungs. It was originally named for its potent vasodilatory effects in the gut but has since been recognized as a pleiotropic regulatory molecule with profound anti-inflammatory, bronchodilatory, neuroprotective, chronobiotic (circadian rhythm-regulating), and immunomodulatory functions. VIP signals through VPAC1 and VPAC2 G-protein-coupled receptors expressed in the hypothalamus, lung, small intestine, immune cells, pituitary gland, and vascular smooth muscle, producing a coordinated response that simultaneously relaxes smooth muscle, suppresses inflammatory cytokine production, promotes regulatory T cell development, and supports MSH production from the hypothalamic pituitary axis.
In the lungs, VIP is produced by non-adrenergic non-cholinergic (NANC) neurons and is the primary endogenous bronchodilator and pulmonary vasodilator; VIP-deficient states are associated with pulmonary arterial hypertension (PAH) and airway hyperresponsiveness. In the hypothalamus, VIP produced by suprachiasmatic nucleus neurons regulates circadian rhythm entrainment and is required for normal sleep-wake cycle maintenance. In immune cells, VIP binds VPAC1 and VPAC2 on T cells, macrophages, and dendritic cells, potently suppressing NF-kB activation and the downstream production of IL-6, TNF-alpha, IL-12, and MMP-9 while promoting IL-10 and TGF-beta1 regulatory signaling. Through its stimulation of hypothalamic POMC processing, VIP also supports MSH production, making it a proximal regulator of the MSH-dependent systems that are disrupted in CIRS.
In the Shoemaker CIRS protocol, VIP is measured as a diagnostic marker of biotoxin-driven regulatory neuropeptide depletion and used therapeutically as a compounded nasal spray in the final stages of the treatment sequence. Low VIP is found in a significant proportion of CIRS patients, particularly those with prominent pulmonary, exercise intolerance, and sleep dysregulation symptoms. Its measurement confirms the extent of regulatory neuropeptide depletion and its normalization with VIP therapy provides the capstone regulatory signal that allows the CIRS inflammatory cascade to fully resolve after upstream treatment steps are completed.
2. Reference Range and Optimal Levels
| VIP Level | Interpretation |
|---|---|
| Below 23 pg/mL | Low: pulmonary, anti-inflammatory, circadian, and MSH-stimulating functions impaired; CIRS-consistent |
| 23 to 28 pg/mL | Low-normal: borderline; evaluate with other CIRS markers, pulmonary symptoms, and sleep quality |
| 28 to 50 pg/mL | Adequate: functional VIP signaling for most regulatory roles |
| 50 to 63 pg/mL | Optimal: full pulmonary vasodilatory, anti-inflammatory, and circadian regulatory capacity |
| Above 63 pg/mL | Elevated: uncommon; consider VIPoma (VIP-secreting neuroendocrine tumor) if markedly elevated with profuse watery diarrhea |
VIP levels require careful specimen handling; VIP is a peptide that degrades at room temperature. Specimens should be collected in EDTA tubes kept on ice and processed promptly. Not all commercial laboratories offer validated VIP assays; specialty reference laboratories should be used for CIRS panel evaluation. VIP has a very short plasma half-life of approximately 1 to 2 minutes, meaning measured serum VIP reflects recent secretion rather than total body VIP status; this is why it can be practically measured even though the native peptide is so short-lived.
3. What Low VIP Produces: Multi-System Consequences
Pulmonary and Cardiovascular Effects
- Pulmonary arterial hypertension (PAH): VIP is the primary endogenous non-adrenergic non-cholinergic pulmonary vasodilator produced by NANC neurons in the lung; VIP deficiency allows pulmonary arterial smooth muscle to remain contracted, elevating pulmonary arterial pressure; the resulting PAH is not structural (there is no vascular disease) but functional, driven by loss of VIP-mediated vasodilation; patients experience the air hunger, exercise-induced dyspnea, and effort intolerance of PAH without the echocardiographic or catheterization findings of fixed structural disease
- Airway hyperresponsiveness: VIP is a potent bronchodilator that balances the bronchoconstricting effects of acetylcholine in airway smooth muscle; VIP deficiency shifts the airway autonomic balance toward bronchoconstriction; CIRS patients with low VIP may develop new-onset asthma-like symptoms or worsening of pre-existing airway disease
- Reduced VEGF: VIP through VPAC receptor signaling on pulmonary endothelial cells stimulates VEGF production and promotes endothelial survival; low VIP contributes to the low VEGF that characterizes the capillary hypoperfusion of CIRS; VIP therapy raises VEGF and restores capillary density and function as part of the integrated pulmonary recovery
- Exercise intolerance and post-exertional malaise: the combination of PAH-like pulmonary hypertension and reduced VEGF-mediated capillary perfusion produces the severe exercise intolerance and post-exertional malaise that are defining features of pulmonary CIRS; these symptoms resolve as VIP therapy restores pulmonary vasodilatory capacity and VEGF rises
Neurological, Immune, and Hormonal Effects
- Circadian rhythm disruption: VIP is produced by suprachiasmatic nucleus (SCN) neurons and coordinates the intercellular coupling of the SCN circadian clock; without adequate VIP signaling, SCN neurons lose their synchronized oscillation, disrupting the master circadian output that regulates sleep-wake cycles, cortisol diurnal rhythm, body temperature cycles, and metabolic timing; CIRS patients with low VIP often describe sleep-wake timing that drifts or fails to respond to normal zeitgebers (light, meals, activity)
- Persistent inflammation: VIP potently suppresses NF-kB activation and downstream MMP-9, IL-6, TNF-alpha, and IL-12 production in macrophages and dendritic cells; VIP deficiency allows these pro-inflammatory cytokines to remain elevated despite other protocol interventions; patients who have completed earlier CIRS steps but have persistently elevated MMP-9 and residual inflammatory markers often have unresolved low VIP as the missing piece
- Impaired MSH production: VIP stimulates hypothalamic POMC processing through VPAC receptor signaling on pituitary corticotrophs and melanotrophs; VIP deficiency directly impairs MSH production from the hypothalamic-pituitary axis; this is why VIP therapy in the final protocol stages is able to restore MSH after MARCoNS eradication has removed the hemolysin-mediated MSH cleavage
- Immune dysregulation: VIP promotes regulatory T cell (Treg) differentiation through VPAC1 signaling and suppresses Th1 and Th17 inflammatory responses; VIP deficiency contributes to the immune imbalance that makes CIRS patients vulnerable to MARCoNS and recurrent mucosal infections; VIP restoration shifts immune balance toward regulation and away from chronic innate immune activation
4. Why VIP Must Be the Last Step in the CIRS Protocol
The requirement that VIP therapy be delayed until after upstream CIRS protocol steps are completed is not a theoretical preference but a pharmacological reality driven by VIP's extremely short half-life and the inflammatory environment of active CIRS.
Native VIP has a plasma half-life of approximately 1 to 2 minutes under normal physiological conditions. In the high-complement, high-cytokine inflammatory environment of active CIRS, this half-life is further shortened by complement-mediated peptide degradation, protease activity from activated macrophages and neutrophils, and the loss of VIP receptor desensitization protection from chronic low-VIP exposure. Administering VIP nasal spray when C4a is markedly elevated (for example, 25,000 ng/mL) results in the exogenously administered VIP being degraded within seconds of reaching the systemic circulation, before it can act on its target VPAC receptors in pulmonary endothelium, hypothalamus, or immune cells. The clinical result is minimal benefit and potential patient frustration from investing in an expensive compounded medication that produces no measurable improvement.
Completing steps 1 through 9 of the Shoemaker protocol creates the biochemical environment in which administered VIP can survive long enough to act: normalized C4a reduces complement-driven VIP degradation, reduced TGF-beta1 reduces the macrophage protease activity that cleaves VIP, eradicated MARCoNS removes the hemolysin source that was preventing MSH recovery (which VIP can now stimulate), and corrected androgen and ADH levels restore the hormonal context for effective VIP signaling. In this environment, each dose of VIP nasal spray survives long enough to bind its VPAC receptors and produce the measurable improvements in MMP-9 reduction, VEGF elevation, MSH stimulation, and pulmonary vasodilation that characterize successful VIP therapy.
5. VIP Nasal Spray: Clinical Protocol Details
- Formulation: compounded VIP nasal spray at 50 micrograms per actuation; must be prepared by a compounding pharmacy experienced with peptide formulations; requires refrigeration and has limited stability (typically 30 to 60 days refrigerated); confirm potency and stability at the time of dispensing
- Dosing protocol: 50 micrograms (1 actuation) each nostril, 4 times daily; total daily dose 400 micrograms; timed with inhalations to maximize pulmonary deposition; some providers prescribe a trial dose period of 4 to 6 weeks with laboratory monitoring before committing to extended therapy
- Monitoring during VIP therapy: recheck VEGF, MMP-9, MSH, VIP, and clinical VCS testing at 30-day intervals; VEGF rising, MMP-9 falling, and MSH rising toward 40 to 60 pg/mL confirm appropriate VIP response; clinical improvement in air hunger, sleep quality, and cognitive symptoms should be evident within 4 to 8 weeks of effective therapy
- Safety considerations: VIP nasal spray is generally well-tolerated; transient facial flushing or mild headache from the vasodilatory effects may occur with initial doses and typically resolve; VIP should not be started if there is any ongoing biotoxin exposure because this will produce no benefit and may worsen patient frustration; blood pressure monitoring is reasonable in patients with hypotension at baseline
- When VIP does not work: failure of expected laboratory improvements with VIP therapy after 30 to 60 days signals that an upstream step was incompletely addressed; most commonly: an unidentified ongoing biotoxin exposure source, incompletely eradicated MARCoNS, or insufficient C4a normalization; systematic review of all protocol steps is required before concluding that VIP therapy is ineffective
6. Supporting VIP Recovery and Signaling
Protocol Prerequisites
- Confirmed biotoxin exposure elimination: ERMI documentation that the home and workplace are clear; no ongoing water-damaged building exposure during VIP therapy
- C4a normalized to below 2,830 ng/mL: complement activation must be substantially resolved before VIP can survive long enough to act; do not start VIP with markedly elevated C4a
- TGF-beta1 reduced toward normal: losartan therapy completed and TGF-beta1 moving toward below 2,380 pg/mL before introducing VIP
- MARCoNS eradicated and confirmed by repeat culture: hemolysin production from persistent MARCoNS will continue to prevent MSH recovery and will blunt VIP's ability to stimulate MSH production
- Androgen and ADH correction completed: hormonal context must be restored for VIP signaling to function optimally through the hypothalamic-pituitary axis
Nutritional VIP Support
- Adequate protein intake: VIP is a peptide requiring amino acid precursors for synthesis; protein intake of at least 1.2g per kg body weight daily supports endogenous VIP production alongside exogenous supplementation
- B vitamin sufficiency: VIP synthesis and receptor signaling require thiamine (B1), riboflavin (B2), niacinamide (B3), and pyridoxine (B6) as cofactors; B vitamin complex supplementation during VIP therapy supports both production and downstream signaling
- Magnesium optimization: VPAC receptor signal transduction is magnesium-dependent; magnesium deficiency impairs the intracellular cAMP signaling cascade activated by VIP-VPAC binding; target RBC magnesium of 5.5 to 6.4 mg/dL
- Anti-inflammatory diet: continued Mediterranean or anti-inflammatory dietary pattern reduces the macrophage and mast cell protease activity that accelerates VIP degradation; omega-3 fatty acids (3 to 4g EPA and DHA daily) support the anti-inflammatory environment that allows VIP to act
- Avoid alcohol: alcohol increases VIP degradation by activating hepatic and intestinal peptide-degrading enzymes; abstinence during VIP therapy maximizes bioavailability of each administered dose
Sleep and Circadian Support
- Consistent sleep-wake timing: VIP regulates SCN circadian synchronization; consistent daily sleep and wake times reinforce the circadian signal that VIP therapy is restoring; irregular sleep timing counteracts VIP's chronobiotic benefits
- Light exposure management: morning bright light exposure (10 to 30 minutes within 30 minutes of waking) activates the SCN circuit that VIP regulates; evening blue light avoidance reduces circadian signal disruption; these behavioral zeitgebers support VIP-mediated SCN recovery
- Melatonin (0.5 to 1mg 2 hours before target sleep): low-dose melatonin supports circadian entrainment through MT1 and MT2 receptor signaling in the SCN that complements VIP's VPAC-mediated SCN coupling; use only low doses to avoid receptor desensitization
- Temperature management: the SCN-regulated body temperature drop at sleep onset (0.5 to 1 degree Celsius) is partly VIP-mediated; sleeping in a cool environment (65 to 68 degrees Fahrenheit) supports this temperature signal while VIP circadian regulation is recovering
7. Related Lab Tests
MSHVIP Directly Stimulates MSH Production; Both Are Restored Together with VIP Therapy
→
VEGFVIP Raises VEGF and Restores Capillary Perfusion; Both Track Together
→
MMP-9VIP Directly Reduces MMP-9 Through NF-kB Suppression
→
C4aMust Normalize Before VIP Therapy Is Pharmacologically Effective
→
TGF-beta1Must Reduce Before VIP Therapy Is Introduced in Protocol Sequence
→
ACTHShares Hypothalamic-Pituitary Regulatory Context with VIP-Stimulated MSH
→
8. Clinical Perspective
Clinical Perspective
VIP is what I think of as the master key in CIRS treatment, and the clinical experience of using it correctly is one of the most rewarding in my practice. When a patient has completed steps 1 through 9 of the protocol, their C4a has normalized, their TGF-beta1 is back below threshold, MARCoNS has been eradicated by culture confirmation, and yet they still have air hunger when they climb stairs, persistent sleep disruption, and cognitive symptoms that are better but not resolved, the missing piece is almost always that VIP remains below 23 pg/mL. These patients feel tantalizingly close to recovery but stuck. Introducing VIP nasal spray at that stage, in that biological environment where upstream contributors have been addressed, produces the kind of clinical response that reminds me why I practice medicine: the air hunger begins to resolve within two to four weeks, sleep quality improves, the residual brain fog lifts, and when we recheck the laboratory at 30 days, the MMP-9 has dropped, the VEGF has risen, and the MSH is finally beginning to move upward. That cascade of laboratory and clinical improvement from a single intervention used at the right biological moment is the most compelling demonstration I know of why sequence matters in complex illness. VIP at step 2 of the protocol is expensive and ineffective. VIP at step 10, in the right biological environment, can be transformative.
Brian Lamkin, DO | Founder, The Lamkin Clinic | Edmond, Oklahoma
9. Frequently Asked Questions
Why must earlier CIRS protocol steps be completed before VIP therapy is started?
VIP has an extremely short plasma half-life of approximately 1 to 2 minutes that is further shortened in the high-complement, high-protease inflammatory environment of active CIRS. Administering VIP nasal spray when C4a is markedly elevated results in the peptide being degraded before it can act on its VPAC receptor targets. Completing steps 1 through 9 (exposure elimination, binders, MARCoNS eradication, androgen correction, ADH normalization, and C4a and TGF-beta1 reduction) creates the biochemical environment where administered VIP survives long enough to produce its effects on MMP-9, VEGF, MSH, and pulmonary vasodilation.
What clinical improvements can be expected from VIP nasal spray therapy?
Patients who receive VIP nasal spray after appropriate upstream protocol completion typically experience: progressive resolution of air hunger and exercise-induced dyspnea (from restored pulmonary vasodilation) within 2 to 4 weeks, improvement in sleep quality and circadian rhythm stability, further reduction in brain fog and cognitive symptoms as MMP-9 falls and VEGF rises, and rising MSH levels that consolidate the regulatory improvements achieved by earlier protocol steps. Complete resolution of pulmonary symptoms may require 3 to 6 months of continued therapy with protocol adherence.
Is VIP nasal spray available commercially?
VIP nasal spray is a compounded peptide formulation prepared by specialized compounding pharmacies; it is not commercially available as an FDA-approved drug in nasal spray form. It requires a prescription from a provider experienced with the Shoemaker CIRS protocol and compounding pharmacy preparation. Cost varies by pharmacy and formulation but is typically a significant ongoing expense. Insurance coverage is rare; most patients pay out of pocket. The peptide has limited stability once compounded and must be refrigerated.
Can VIP therapy worsen CIRS symptoms?
VIP nasal spray used before upstream protocol steps are completed can produce minimal benefit or mild temporary worsening in some patients as the short-lived peptide fragments produced by its rapid degradation may create transient signaling disruption. VIP is not dangerous in this context but is expensive and ineffective when used prematurely. In patients with unresolved ongoing biotoxin exposure, VIP therapy will produce no lasting improvement because the upstream biotoxin stimulus continues to suppress VIP and all other downstream regulatory markers.
What is the VIPoma and why is very elevated VIP a concern?
A VIPoma is a rare neuroendocrine tumor (usually pancreatic) that produces massive amounts of VIP, causing a clinical syndrome known as Verner-Morrison syndrome or WDHA syndrome (watery diarrhea, hypokalemia, achlorhydria). Markedly elevated VIP (above 100 to 200 pg/mL) in a patient with profuse watery diarrhea and electrolyte abnormalities requires immediate evaluation for VIPoma with imaging. In the CIRS context, VIP is expected to be low to normal; markedly elevated VIP in a CIRS evaluation is not a CIRS finding and requires oncological investigation.
Content authored and clinically reviewed by Brian Lamkin, DO, founder of The Lamkin Clinic in Edmond, Oklahoma. Brian Lamkin, DO has 25+ years of experience in functional and regenerative medicine. This page reflects current functional medicine practice standards and is updated as new clinical evidence becomes available.
Low VIP is the final regulatory depletion of CIRS that explains persistent air hunger, sleep disruption, and residual inflammation even after earlier treatment steps succeed. Its restoration with VIP nasal spray at the right protocol stage is the capstone of CIRS recovery.
VIP evaluation and therapy require precise protocol sequencing. Schedule a consultation for a comprehensive CIRS evaluation and structured recovery plan including VIP assessment and therapy planning.
Schedule a ConsultationMedical Disclaimer: This content is provided for educational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Lab interpretation should always be performed in clinical context by a qualified healthcare provider. Reference ranges and optimal targets may vary based on individual patient history, clinical presentation, and laboratory methodology. Schedule a consultation to discuss your specific results with Dr. Lamkin.