Vasoactive intestinal peptide, usually shortened to VIP, is a 28-amino-acid neuropeptide first isolated from porcine duodenum in 1970 by Sami Said and Viktor Mutt. It’s part of the secretin\/glucagon peptide family, which also includes GLP-1, GLP-2, GIP, and PACAP. VIP is widely distributed through the nervous system and gastrointestinal tract, with major roles in smooth muscle relaxation, vasodilation, immune modulation, and circadian regulation.<\/p>\n
In medicine, intranasal VIP has been studied in sarcoidosis, chronic inflammatory response syndrome, and a handful of mold-illness protocols popularized by Ritchie Shoemaker. Aviptadil, a synthetic VIP analog, has been studied in pulmonary hypertension and was tested in severe COVID-19 ARDS with mixed results. Outside these specific contexts, VIP is mostly a peptide used off-label by integrative medicine clinicians for “biotoxin illness” or general inflammation, without strong evidence.<\/p>\n
This article separates the genuine physiology and clinical trial data from the consumer protocols.<\/p>\n
At TrimRx, we believe that understanding your options is the first step toward a more manageable health journey. You can take the free assessment quiz if you’re ready to see whether a personalized program is a fit for you.<\/p>\n
VIP is encoded by the VIP gene and processed from a precursor protein into a 28-amino-acid mature peptide.<\/strong> It’s produced widely, in enteric neurons throughout the gut, in central nervous system neurons including the suprachiasmatic nucleus that controls circadian rhythm, in immune cells, and in some endocrine cells of the pancreas and other organs.<\/p>\n Quick Answer: VIP is a 28-amino-acid neuropeptide with vasodilator, anti-inflammatory, and immune-modulating effects<\/p>\n The receptors VPAC1 and VPAC2 are G-protein coupled receptors expressed on many cell types including T cells, dendritic cells, vascular smooth muscle, gut epithelium, and lung tissue. PAC1 is a related receptor that binds PACAP preferentially and VIP with lower affinity.<\/p>\n Through these receptors, VIP triggers cAMP-mediated signaling that drives smooth muscle relaxation, vasodilation, anti-inflammatory cytokine shifts (less TNF-alpha and IL-6, more IL-10), and several effects on circadian regulation in the SCN.<\/p>\n Aviptadil is the synthetic version of human VIP, identical in sequence.<\/strong> It’s been developed by several companies for pulmonary indications because VIP relaxes pulmonary vasculature and bronchial smooth muscle. NRx Pharmaceuticals (formerly Relief Therapeutics) has held aviptadil under the brand Zyesami for COVID-19 development.<\/p>\n The COVID-19 program included the TESICO trial, a 538-patient placebo-controlled trial in severe COVID-19 ARDS published in JAMA 2023. The primary endpoint of survival without respiratory failure at 90 days didn’t show a significant benefit. Some subgroup analyses suggested signal in patients on high-flow oxygen without mechanical ventilation, but the trial didn’t support FDA approval for the indication.<\/p>\n For pulmonary hypertension and ARDS more broadly, aviptadil remains investigational.<\/p>\n Ritchie Shoemaker is a physician who developed a framework called chronic inflammatory response syndrome (CIRS), often attributed to water-damaged building exposure and biotoxin illness.<\/strong> His protocol involves a multi-step process that ends, in some patients, with intranasal VIP administration after other inflammatory markers have been normalized.<\/p>\n The claimed mechanism is that VIP restores normal immune-neuroendocrine signaling in patients whose hypothalamic-pituitary axis has been dysregulated by chronic biotoxin exposure. Reported outcomes include improvement in transformed grayscale visual contrast sensitivity scores, reduction in C4a complement levels, and symptomatic improvement in fatigue and cognitive dysfunction.<\/p>\n Independent randomized trial replication of this protocol doesn’t exist. Most published Shoemaker literature is case series or registry data from the Shoemaker clinic and aligned practitioners. Mainstream rheumatology, infectious disease, and environmental medicine organizations don’t endorse the CIRS framework.<\/p>\n VIP is a potent pulmonary vasodilator in animal studies.<\/strong> Patients with pulmonary arterial hypertension have been shown to have reduced VIP levels in lung tissue and serum. These observations motivated early-stage trials of inhaled aviptadil in PAH.<\/p>\n Small open-label studies in the 2000s suggested hemodynamic improvements with inhaled aviptadil. Larger placebo-controlled trials haven’t replicated the findings convincingly, and aviptadil hasn’t replaced sildenafil, endothelin receptor antagonists, prostacyclin analogs, or the newer riociguat as standard PAH therapy.<\/p>\n The PAH indication remains exploratory and aviptadil isn’t FDA-approved for it.<\/p>\n Animal models of colitis show that VIP reduces inflammation, possibly by shifting T-cell responses toward regulatory phenotypes and reducing pro-inflammatory cytokine production.<\/strong> Several small human studies have measured circulating VIP in Crohn disease and ulcerative colitis, with inconsistent results.<\/p>\n No phase 2 or 3 trial of VIP or aviptadil as primary therapy for IBD has been published. IBD treatment continues to evolve around TNF inhibitors, integrin inhibitors, JAK inhibitors, IL-23 inhibitors, and S1P modulators. VIP isn’t part of standard IBD care.<\/p>\n The Shoemaker protocol typically uses intranasal VIP at 50 micrograms per spray, four sprays daily (around 200 micrograms per day), compounded by specialty pharmacies.<\/strong> Dosing usually starts after other CIRS markers like MMP-9, C4a, TGF-beta-1, and VEGF have been addressed with prior protocol steps.<\/p>\n Compounding pharmacies that prepare intranasal VIP do so under section 503A for individual patient prescriptions. The product isn’t FDA-approved, and the bulk drug substance status of VIP for compounding has been variable across FDA review cycles.<\/p>\n Patients are typically monitored with periodic labs including a CIRS marker panel and visual contrast sensitivity testing. The therapy is open-ended for some patients, with treatment durations of months to years depending on response.<\/p>\n Key Takeaway: Intranasal VIP is popularized by Shoemaker biotoxin illness protocols but lacks randomized trial support<\/p>\n In short-term studies and clinical use, VIP is generally well-tolerated.<\/strong> Reported side effects include facial flushing (from vasodilation), nasal irritation with intranasal use, transient headache, and rare hypotension at higher systemic doses.<\/p>\n The bigger safety question is whether long-term VIP signaling in patients without a documented deficit produces unintended effects. VPAC1 and VPAC2 are widely expressed, and chronic agonism could in principle influence T-cell function, vascular tone, and pancreatic endocrine function. These haven’t shown up as clinical problems in the limited follow-up available.<\/p>\n For patients receiving compounded intranasal VIP outside clinical trials, the regulatory and quality assurance layer is thinner than for FDA-approved products.<\/p>\n Mast cell activation syndrome (MCAS) is sometimes invoked in CIRS protocols.<\/strong> VIP’s anti-inflammatory profile and effects on mast cell signaling have led to its use in some MCAS contexts, though the evidence base is anecdotal.<\/p>\n For confirmed MCAS, mainstream care includes H1 and H2 antihistamines, mast cell stabilizers like cromolyn, leukotriene inhibitors, and in some cases anti-IgE therapy. VIP isn’t a standard part of those algorithms.<\/p>\n VIP isn’t a weight loss peptide or a diabetes drug.<\/strong> It’s an anti-inflammatory neuropeptide with niche uses in pulmonary medicine, mold illness protocols, and some other inflammatory contexts.<\/p>\n For weight loss and cardiometabolic disease, the GLP-1 class has the strongest data. STEP 1 (Wilding 2021 NEJM) showed 14.9% weight loss with semaglutide at 68 weeks. SURMOUNT-1 (Jastreboff 2022 NEJM) showed 20.9% with tirzepatide. SELECT (Lincoff 2023 NEJM) showed 20% MACE reduction with semaglutide in patients with cardiovascular disease and overweight or obesity. FLOW (Perkovic 2024 NEJM) showed 24% kidney and cardiovascular death reduction.<\/p>\n TrimRx is a telehealth platform that offers compounded semaglutide and tirzepatide. The free assessment quiz determines if you qualify for a personalized treatment plan.<\/p>\n If you have a specific clinical context where VIP is being considered, like documented CIRS by a clinician trained in that framework, the decision is between you and your prescriber, with the caveat that the framework itself isn’t mainstream-supported.<\/strong><\/p>\n For general anti-inflammatory effects, fatigue, brain fog, or unspecified chronic symptoms, the evidence supporting VIP is weak. Better-evidenced interventions for those symptoms include working up specific underlying causes (thyroid, anemia, sleep apnea, depression, autoimmune disease) and addressing them directly.<\/p>\n Bottom line: The peptide has a short half-life, around 2 minutes in circulation, which complicates dosing<\/p>\n Vasoactive intestinal peptide. It was named after its discovery in intestinal tissue and its vasodilator effects, though it’s now known to be widely distributed beyond the gut.<\/p>\n No. VIP and GLP-1 are both in the secretin\/glucagon peptide family and share some structural similarity, but they have different receptors, different physiological roles, and very different clinical use cases. GLP-1 agonists are blockbuster weight loss and diabetes drugs. VIP is a niche peptide with limited indications.<\/p>\n No. Intranasal VIP is prepared by compounding pharmacies for individual patients under section 503A. There’s no FDA-approved VIP product for chronic inflammatory response syndrome, mold illness, or related indications.<\/p>\n There’s no published randomized trial of VIP for long COVID. Some integrative medicine practitioners use it based on the CIRS framework, but mainstream long COVID research focuses on other mechanisms and interventions.<\/p>\n Native VIP has a circulating half-life of about 2 minutes, which is why intranasal administration with frequent dosing is preferred. Longer-acting VIP analogs have been developed but aren’t widely available.<\/p>\n The TESICO trial published in JAMA 2023 didn’t show survival benefit in severe COVID-19 ARDS. Some subgroup signals existed but the trial didn’t support FDA approval for that use.<\/p>\n Major contraindications haven’t been formally established because the product isn’t FDA-labeled. Caution applies in patients with severe hypotension, significant vascular disease, or known hypersensitivity. Pregnancy and lactation safety hasn’t been characterized.<\/p>\n Disclaimer:<\/strong> This content is for informational purposes only and does not constitute medical advice. It is not intended to diagnose, treat, cure, or prevent any disease or condition. Individual results may vary. Always consult a qualified healthcare professional before starting any weight loss program or medication.<\/p>\n","protected":false},"excerpt":{"rendered":" Introduction Vasoactive intestinal peptide, usually shortened to VIP, is a 28-amino-acid neuropeptide first isolated from porcine duodenum in 1970 by Sami Said and Viktor…<\/p>\n","protected":false},"author":11,"featured_media":90932,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"inline_featured_image":false,"_yoast_wpseo_title":"Vasoactive Intestinal Peptide (VIP): Gut-Brain Healing","_yoast_wpseo_metadesc":"Vasoactive intestinal peptide, usually shortened to VIP, is a 28-amino-acid neuropeptide first isolated from porcine duodenum in 1970 by Sami Said and...","_yoast_wpseo_focuskw":"vip gut brain","footnotes":"","_flyrank_wpseo_metadesc":""},"categories":[19],"tags":[],"class_list":["post-90933","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-longevity"],"_links":{"self":[{"href":"https:\/\/trimrx.com\/blog\/wp-json\/wp\/v2\/posts\/90933","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/trimrx.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/trimrx.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/trimrx.com\/blog\/wp-json\/wp\/v2\/users\/11"}],"replies":[{"embeddable":true,"href":"https:\/\/trimrx.com\/blog\/wp-json\/wp\/v2\/comments?post=90933"}],"version-history":[{"count":1,"href":"https:\/\/trimrx.com\/blog\/wp-json\/wp\/v2\/posts\/90933\/revisions"}],"predecessor-version":[{"id":92018,"href":"https:\/\/trimrx.com\/blog\/wp-json\/wp\/v2\/posts\/90933\/revisions\/92018"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/trimrx.com\/blog\/wp-json\/wp\/v2\/media\/90932"}],"wp:attachment":[{"href":"https:\/\/trimrx.com\/blog\/wp-json\/wp\/v2\/media?parent=90933"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/trimrx.com\/blog\/wp-json\/wp\/v2\/categories?post=90933"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/trimrx.com\/blog\/wp-json\/wp\/v2\/tags?post=90933"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}What Is Aviptadil and How Is It Different From Native VIP?<\/h2>\n
What Does the Shoemaker CIRS Protocol Claim About VIP?<\/h2>\n
What’s the Evidence in Pulmonary Hypertension?<\/h2>\n
Has VIP Been Studied in Inflammatory Bowel Disease?<\/h2>\n
How Is Intranasal VIP Dosed in Clinical Use?<\/h2>\n
What Are the Side Effects?<\/h2>\n
What About VIP and Mast Cell Activation?<\/h2>\n
How Does This Fit Into Metabolic Health?<\/h2>\n
Should You Try Intranasal VIP?<\/h2>\n
FAQ<\/h2>\n
What Does VIP Stand For?<\/h3>\n
Is VIP the Same as GLP-1?<\/h3>\n
Is Intranasal VIP FDA-approved?<\/h3>\n
Can VIP Help with Long COVID?<\/h3>\n
What’s the Half-life of VIP?<\/h3>\n
Did Aviptadil Work for COVID-19?<\/h3>\n
Are There Contraindications for VIP?<\/h3>\n