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 synthetic eight-amino-acid peptide taken by mouth. It was designed to act locally in the small intestine and is not meant to be absorbed. It was developed first by Alba Therapeutics, then Innovate Biopharmaceuticals, and finally 9 Meters Biopharma, always for 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 that loosens the tight junctions, the protein seals between intestinal cells. The idea was that blocking zonulin would keep gluten fragments from slipping between cells and triggering the immune reaction that damages the intestine. ¹

How it works

Tight junctions are the structures that hold adjacent intestinal cells together and control what passes between them. In celiac disease, gluten peptides trigger zonulin release, zonulin opens the junctions, and more gluten reaches the immune cells under the surface. Larazotide was shown in cell and animal work to oppose that opening and keep the junctions closed. ¹

Because larazotide stays in the gut, any effect depends on it being present when gluten arrives, which shaped the trial designs: three of the four earlier trials gave patients a fixed daily amount of gluten (a gluten challenge) and two tested patients on their usual gluten-free diet, and the phase 3 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, with 626 patients. In patients given a daily gluten challenge, larazotide improved gastrointestinal symptom scores and reduced 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, the intestinal permeability measure the drug was designed to change, did not differ from placebo. ³

The phase 3 trial, CedLara, enrolled adults with celiac disease who still had symptoms on a gluten-free diet and compared two larazotide doses with placebo over 12 weeks. An interim analysis of about half the planned 525 patients in June 2022 found that the number of additional patients needed to show a significant difference was too large to justify continuing, and 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, mostly headache and gastrointestinal complaints, which fits a drug that is barely absorbed. No serious safety signal was reported. ³

What is unknown is long-term exposure; the trials ran weeks to a few months, and 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, and 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, and 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 and 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, which 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