VIP vs Larazotide acetate
Comprehensive side-by-side comparison of mechanisms, dosing, side effects, and research
Also: Vasoactive Intestinal Peptide, Aviptadil
VIP (vasoactive intestinal peptide) is a 28-amino-acid signaling peptide your own gut, nerves, and immune cells make, first isolated in 1970 by Said and Mutt. It is a natural anti-inflammatory and a potent vasodilator, and a synthetic version called aviptadil was tested in humans for COVID-19 respiratory failure, where the largest trial was negative. No VIP product is FDA-approved, including for the wellness, anti-aging, or mold-illness uses it gets marketed for.
Also: Larazotide, AT-1001
Larazotide is an 8-amino-acid oral peptide (GGVLVQPG) designed to tighten the junctions between gut lining cells, aimed at celiac disease. For years it was the furthest-along celiac drug in development and it gets talked about online as a 'leaky gut' or zonulin blocker. The honest story is short: one phase 2b trial found a modest symptom benefit at the lowest dose only, the phase 3 trial was stopped in 2022 when it could not show a clear effect, and the sponsor 9 Meters Biopharma filed for Chapter 7 liquidation in July 2023. It is not approved anywhere.
Key Comparison Insights
- Both peptides belong to the Immune category, suggesting similar primary applications.
Detailed Comparison
| Attribute | VIP | Larazotide acetate |
|---|---|---|
| Category | Immune | Immune |
| FDA Status | Not FDA Approved | Not FDA Approved |
| Clinical Status | Pre I II III IV FDA | Pre I II III IV FDA |
| Mechanism of Action | VIP works through two G-protein-coupled receptors, VPAC1 and VPAC2, which are spread across immune cells, the gut, blood vessels, and the brain. When VIP binds, the receptor raises intracellular cyclic AMP, and that signal relaxes smooth muscle (so blood vessels and airways dilate) and tamps down inflammatory signaling. On the immune side, that rise in cAMP blunts NF-kB activity and lowers pro-inflammatory cytokines like TNF-alpha, which is the basis for calling VIP an endogenous anti-inflammatory. The same pathway is why researchers looked at it for the runaway lung inflammation seen in severe COVID-19. It is a broadly active hormone, not a targeted single-tissue drug, which is part of why dosing it safely is tricky. | Larazotide is modeled on a fragment of Vibrio cholerae zonula occludens toxin, a region that overlaps with zonulin, the human protein that loosens tight junctions in the gut wall. The idea is that it blocks zonulin signaling and helps tight junctions reassemble, so gluten fragments have a harder time slipping between cells into the tissue underneath, where they trigger the immune reaction in celiac disease. It acts locally in the gut lumen and is not meant to be absorbed. That is a reasonable hypothesis with lab and animal support, but it is worth being clear: larazotide does not stop the immune response to gluten itself, and no human trial proved it protects the gut lining on biopsy. |
| Common Dosing | 50-100 mcg daily 1-2x daily | 0.5 mg three times daily before meals (trial dose) Three times daily, before meals |
| Administration | IV infusion, inhaled, or intranasal | Oral capsule taken before meals, alongside a gluten-free diet (not instead of it) |
| Typical Duration | Variable by indication | 12 weeks of treatment in the phase 2b trial |
| Best Time to Take | Morning or as directed | About 15 minutes before each main meal (trial protocol) |
Possible Side Effects May vary by individual |
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| Research Summary | Most of the real human data on VIP comes from aviptadil, the synthetic version (code RLF-100, brand Zyesami, developed by NRx Pharmaceuticals and Relief Therapeutics). A randomized trial of intravenous aviptadil in critically ill COVID-19 patients (about 196 patients, Critical Care Medicine 2022) missed its primary endpoint, with only exploratory signals. The bigger NIH ACTIV-3b/TESICO trial (Lancet Respiratory Medicine 2023, 461 patients) was clearly negative: no benefit on the 90-day recovery scale (odds ratio 1.11, p=0.54), 90-day deaths of 38% vs 36% on placebo, and it was stopped early for futility. The FDA declined emergency use authorization for COVID-19. Outside the US, aviptadil combined with phentolamine (Invicorp) is licensed as an injection for erectile dysfunction in the UK and some other European countries. VIP and its VPAC receptors are also studied in rheumatoid arthritis, pulmonary hypertension, and other inflammatory conditions, but that work is largely early-stage. There is no trial support for the anti-aging, wellness, or CIRS/mold claims VIP is sold for online. Bottom line: an interesting immune-modulating peptide, but its serious trials did not show it works. | The key human study is a phase 2b trial published in Gastroenterology in 2015 (Leffler and colleagues, NCT01396213). It randomized 342 adults with celiac disease who still had symptoms on a gluten-free diet to 0.5 mg, 1 mg, or 2 mg three times daily or placebo for 12 weeks. Only 0.5 mg met the primary endpoint (symptom score 2.59 vs 2.88), with 26% fewer symptomatic days. The 1 mg and 2 mg doses did nothing measurable, an odd inverse dose response the authors could not explain (peptide aggregation was one guess), and most secondary endpoints missed. Safety looked similar to placebo. The phase 3 CedLara trial (NCT03569007) then tested the same 0.5 mg dose, but in June 2022 an interim analysis showed the number of patients needed to separate drug from placebo was too large to continue, and the trial was terminated. 9 Meters later pointed larazotide at COVID-related conditions such as MIS-C, then filed Chapter 7 in July 2023. We found no active development after that. Bottom line: one positive-ish phase 2b, one stopped phase 3, no approval. |
Frequently Asked Questions: VIP vs Larazotide acetate
What is the difference between VIP and Larazotide acetate?
VIP is a immune peptide that vip (vasoactive intestinal peptide) is a 28-amino-acid signaling peptide your own gut, nerves, and immune cells make, first isolated in 1970 by said and mutt. it is a natural anti-inflammatory and a potent vasodilator, and a synthetic version called aviptadil was tested in humans for covid-19 respiratory failure, where the largest trial was negative. no vip product is fda-approved, including for the wellness, anti-aging, or mold-illness uses it gets marketed for. Larazotide acetate is a immune peptide that larazotide is an 8-amino-acid oral peptide (ggvlvqpg) designed to tighten the junctions between gut lining cells, aimed at celiac disease. for years it was the furthest-along celiac drug in development and it gets talked about online as a 'leaky gut' or zonulin blocker. the honest story is short: one phase 2b trial found a modest symptom benefit at the lowest dose only, the phase 3 trial was stopped in 2022 when it could not show a clear effect, and the sponsor 9 meters biopharma filed for chapter 7 liquidation in july 2023. it is not approved anywhere. The main differences lie in their mechanisms of action and clinical applications.
Which is better, VIP or Larazotide acetate?
Neither is universally "better" - the choice depends on your specific goals. VIP is typically used for immune purposes, while Larazotide acetate is used for immune. Always consult with a healthcare provider to determine which may be appropriate for your situation.
Can VIP and Larazotide acetate be used together?
Some peptide protocols combine multiple compounds for synergistic effects. However, using VIP and Larazotide acetate together should only be considered under medical supervision, as both compounds have their own side effect profiles and potential interactions. Research on their combined use may be limited.