Overview
The furthest any "leaky gut" therapy has progressed through formal drug development — all the way to phase 3, where it failed. That result is important context for the intestinal-permeability claims made across the supplement industry.
Investigational — not approvedInvestigational; development discontinued.
| Regulatory status | Reached phase 3 for celiac disease; the trial did not meet its primary endpoint and was discontinued in 2022. Not approved. |
|---|---|
| Drug class | Octapeptide tight-junction regulator (zonulin antagonist) |
| Route | Oral |
| Half-life | Minimal systemic absorption — acts locally in the gut lumen |
| Evidence rating |
3/5 Moderate
Evidence rating 3 out of 5: Moderate
Small or early-phase human trials, or good controlled topical human data. |
| Studied in | Multiple phase 2 trials in celiac disease showing symptom benefit; the CeDLara phase 3 trial, stopped for futility at interim analysis. |
How it works
Antagonises zonulin signalling to tighten intestinal epithelial tight junctions, reducing paracellular passage of gliadin peptides. It is designed to act locally in the gut lumen with negligible systemic absorption.
Evidence base
Rated 3 of 5 — Moderate. Small or early-phase human trials, or good controlled topical human data.
- A well-run program with a negative definitive result — genuinely useful evidence.
Benefits & potential uses
Bars indicate how well each claim is supported: three = strong human evidence, two = moderate, one = preliminary or preclinical.
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Phase 2 symptom improvement in celiac disease Moderate evidence
Earlier randomized trials showed reduced gastrointestinal symptoms in patients on a gluten-free diet with persistent symptoms.
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Excellent safety profile Strong evidence
Negligible systemic absorption; adverse events comparable to placebo across a large trial program.
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Validated a mechanism Moderate evidence
Demonstrated that tight-junction modulation is pharmacologically achievable, even if the clinical payoff was not delivered.
Risks, cons & cautions
Bars indicate seriousness: three = serious or common, two = moderate, one = minor.
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Failed phase 3 Serious
The definitive trial stopped for futility. This is the most important thing to know about it.
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Not available Moderate evidence
No approved product; no lawful supply.
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Headache and gastrointestinal symptoms Minor
The most commonly reported events, generally mild.
Who should avoid it
- Not applicable — no lawful supply exists
If used under medical supervision, monitor
- Not applicable
Commonly confused with
These mix-ups cause real harm — two products sold under one name, or two molecules whose effects run in opposite directions.
Both marketed for "leaky gut". Larazotide is the only tight-junction drug to reach phase 3 — where it failed. BPC-157 has never had a published randomized human trial at all.
Compare side by sideRegulatory & legal status
Investigational; development discontinued.
Infographic
Where to read further
We link to live literature searches rather than a frozen citation list, so you always see current results — including anything published after our last review.
- PubMed — all published literature on Larazotide Acetate
- PubMed — randomized controlled trials only
- ClinicalTrials.gov — registered human trials
Related peptides in Gut & Gastrointestinal
Terms used on this page
- Phase 3 Trial
- A Phase 3 trial is the large confirmatory study, powered for a prespecified clinical endpoint, on which a marketing application and the resulting product label are built.
- Adverse Event (AE)
- An adverse event is any untoward medical occurrence in someone receiving a medicine, recorded whether or not the drug caused it, which is why an event table is not a harm table.
- Placebo and Placebo Control
- A placebo is an inactive intervention matched to the real one in appearance and route, used as a control arm so that improvement caused by the drug can be separated from improvement that would occur anyway.
This page is educational information, not medical advice. It cannot account for your medical history, medications, or risk factors. Do not start, stop or change any treatment based on it. Speak to a qualified healthcare professional who knows your case.