Larazotide acetate: evidence, FDA status and research

A pill meant to let people with celiac disease handle small amounts of gluten. Trials covering 626 patients gave mixed results, and the last big trial was stopped.

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Larazotide is talked about as a pill that would let people with celiac disease tolerate accidental gluten by tightening the gut barrier, and some wellness sites extend that to 'leaky gut' in general.

Studies say

Randomized trials in celiac patients were run and pooled, but the phase 3 was stopped for lack of effect, so the controlled human evidence (grade B) does not support the claimed benefit.

Why grade B. Larazotide was tested in four randomized placebo-controlled trials in celiac disease with 626 patients in total, pooled in a 2021 meta-analysis, and in a phase 3 trial planned for 525 patients that was stopped at the halfway point. Human controlled data exist, which keeps it at B, but symptom benefit appeared only during deliberate gluten challenge, the permeability measure did not change, and the program ended. ²³

FDA. Not approved by the FDA for any use. Larazotide acetate reached a phase 3 trial for celiac disease, which 9 Meters Biopharma stopped in June 2022 after an interim analysis found it unlikely to show a difference from placebo. ²

Written from 3 cited sources. Fact-checked 2026-10-27: 12 claims checked, 5 corrected. Last refreshed 2026-10-27. Not physician reviewed.

What this means for you

What people take it for: Easing celiac disease symptoms after gluten.
Can a US doctor prescribe it?: No. It is not approved; its last big trial was stopped.
Properly tested in people?: Partly: some human trials, with gaps: four trials in 626 patients, then a big trial stopped early.

Evidence checklist

Randomised controlled trial Several placebo-controlled celiac trialsyes
Human study over 100 people Phase 3 planned for 525, stopped midwayyes
More than one research group One developer line across sponsorsno
Clinical outcomes, not surrogate markers Symptom scores; permeability did not improveno
Human safety data beyond case reports Adverse events similar to placeboyes

Drawn from the cited studies below. A dash means the sources give no information.

What it is

Larazotide acetate is a lab-made peptide of eight amino acids. People take it by mouth. It was designed to act in the small intestine and is not meant to be absorbed. Alba Therapeutics developed it first. Innovate Biopharmaceuticals came next, and then 9 Meters Biopharma. It was always aimed at celiac disease. ¹³

It is described as a zonulin antagonist. Zonulin is a protein released by the gut lining in response to gluten and bacteria. It loosens the tight junctions, the protein seals between intestinal cells. The idea was that blocking zonulin would keep gluten fragments from slipping between cells. That would stop the immune reaction that damages the intestine. ¹

How it works

Tight junctions hold neighbouring intestinal cells together. They control what passes between the cells. In celiac disease, gluten peptides trigger release of zonulin. Zonulin opens the junctions. More gluten then reaches the immune cells under the surface. Cell and animal work showed that larazotide opposes that opening. It keeps the junctions closed. ¹

Larazotide stays in the gut. So any effect depends on it being there when gluten arrives. This shaped the trial designs. Three of the four earlier trials gave patients a set daily amount of gluten (a gluten challenge). Two tested patients on their usual gluten-free diet. The phase 3 trial tested symptoms from ongoing accidental exposure. ³²

What human research shows

A 2021 systematic review and meta-analysis pooled four randomized placebo-controlled trials of larazotide in celiac disease. They covered 626 patients. Some patients got a daily gluten challenge. In them, larazotide improved gut symptom scores. It also cut gluten-related diarrhoea compared with placebo. In patients on a gluten-free diet, there was no difference. Across all trials, the lactulose-to-mannitol ratio did not differ from placebo. This ratio measures gut leakiness (intestinal permeability). The drug was designed to change it. ³

The phase 3 trial was called CedLara. It enrolled adults with celiac disease who still had symptoms on a gluten-free diet. It compared two larazotide doses with placebo over 12 weeks. In June 2022, an interim analysis covered about half of the 525 planned patients. It found that proving a difference would take too many more patients. That was too many to justify going on. The sponsor closed the trial. ²

Study	Model	Finding
Meta-analysis of larazotide RCTs (2021)	Humans, n=626 pooled from four randomized placebo-controlled trials in celiac disease	Symptom scores improved versus placebo during gluten challenge but not on a gluten-free diet; no change in intestinal permeability. ³
CedLara phase 3 (stopped 2022)	Humans, planned n=525, randomized double-blind placebo-controlled, 12 weeks	Interim analysis at roughly half enrollment did not support continuing; the trial was closed and the program ended. ²
Slifer 2021, tight-junction review	Mechanistic review of cell and animal data	Describes zonulin-driven opening of tight junctions and larazotide's blocking action in preclinical systems. ¹

Safety

In the published randomized trials, adverse events with larazotide were similar to placebo. They were mostly headache and gut complaints. That fits a drug that is barely absorbed. No serious safety signal was reported. ³

Long-term exposure is unknown. The trials ran from weeks to a few months. No data exist for the 'leaky gut' uses promoted outside celiac disease. ³

Questions for your clinician

Is there any controlled trial of larazotide for gut symptoms outside celiac disease?
What did the stopped phase 3 trial find?
What proven steps help symptoms on a gluten-free diet?

Questions people ask

Is larazotide acetate FDA-approved?

No. It never reached an approval application. The phase 3 celiac trial was stopped in 2022 after an interim look. 9 Meters moved its resources to other programs. ²

Does larazotide let celiac patients eat gluten?

Not as a licence to eat gluten. Three earlier trials gave patients a small daily gluten challenge. Symptom scores were better with larazotide than placebo. But the permeability measure did not change. The phase 3 tested patients on a gluten-free diet with accidental exposure. It was stopped for lack of a convincing effect. ²³

Is larazotide useful for 'leaky gut'?

There are no human trials of larazotide outside celiac disease. The permeability measure in the celiac trials did not improve. That is the opposite of what the leaky-gut claim would predict. ³

Can I buy larazotide?

It is not an approved drug and has no legitimate retail supply. Products sold online under the name are unregulated and untested. ²

Citations

Slifer 2021, Am J Physiol GI: larazotide acetate, a pharmacological peptide approach to tight junction regulation doi.org
Beyond Celiac 2022: Phase 3 study of larazotide acetate discontinued beyondceliac.org
Hoilat 2022, Clin Res Hepatol Gastroenterol: larazotide acetate for celiac disease, systematic review and meta-analysis of four RCTs doi.org