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Larazotide

Not approved anywhere; phase 3 celiac trial stopped in 2022.

An oral peptide meant to tighten the seals between gut-lining cells. It was the leading drug candidate for until 2022, and is now marketed online for leaky gut. A , also called AT-1001 and INN-202.

C32H55N9O10725.8 g/mol8 amino acids

What the evidence shows

Celiac symptoms despite a gluten-free diet
Failed
In phase 2, only the lowest of three doses beat placebo. The phase 3 trial stopped in June 2022 after an interim look showed it would need far more patients to have a chance of success.
Leaky gut
Lab only
Not a recognized diagnosis, and not tested in a trial.

Side effects and risks

Common
Side effects matched placebo in the trials.

Who should avoid it: Relying on it in place of a gluten-free diet.

How it works

Where it acts
Thought to tighten the junctions between gut-lining cells.
What it changes
Less leakage of gluten fragments through the gut wall in lab studies.
What people notice
Its phase 3 trial in celiac disease stopped for lack of benefit. It was well tolerated.

How it has been given in studies

Capsules of 0.25 mg to 2 mg three times a day, 15 minutes before meals.

Getting it in the United States

This describes what people do. It is not advice. The decision is yours.

What users report

Too few reports to summarize.

More contextCase reports, what public figures say, videos and articles, when options run out and the chemistry

Case reports

From journals, regulators and studies of users. One case proves little.

Benefit reportedtrial result in rare group - 12 people - 2025

Twelve hospitalised children with early MIS-C got larazotide or placebo for 21 days. The drug group cleared gut symptoms and viral spike protein faster and returned to normal activity sooner. No drug-related side effects were reported. Phase 2a only.

Source: Contagion Live, 2025-07

Benefit reportedcase report - 1 person - 2021

One child with MIS-C was given larazotide as a proof of concept. Spike protein in the blood and inflammation markers fell together and the child improved. Single uncontrolled case.

Source: Journal of Clinical Investigation, 2021

What experts and influencers say

Recommend2
Mixed view2
Warn against1

Paraphrased from the linked sources.

Led the 12-child MIS-C trial. Reported that larazotide looked safe and cleared symptoms faster than placebo. Said her team is now testing it in long COVID.

Source: Mass General Brigham, 2025-07

Lael YonkerWebsiteRecommends

Paediatric lung doctor, Mass General Brigham

Money: Co-inventor on a patent for zonulin blockers in MIS-C

Photo source: utswmed.org

Called the halt of the phase 3 celiac trial a disappointment. Said setbacks are expected and the group still aims for treatments or a cure by 2030.

Source: Beyond Celiac, 2022-06

Alice BastSourceMixed view

CEO, Beyond Celiac patient group

When the phase 3 celiac trial was stopped, he pointed to how complex the disease is and how hard it is to measure symptom outcomes.

Source: Beyond Celiac, 2022-06

Patrick GriffinSourceWarns against

Chief medical officer, trial sponsor

Money: Executive at the company developing the drug

Co-author of the MIS-C trial. The hospital release lists his company stake and patent interest next to the positive result.

Source: Mass General Brigham, 2025-07

Alessio FasanoWikipediaRecommends

Paediatric gastroenterologist, larazotide co-developer

Money: Co-founder and stockholder of the company that first developed larazotide. Co-inventor on the MIS-C patent

Watch and read

Explainers, reporting and podcasts worth your time. Summaries are ours. No sellers.

When options run out

Uses people turn to when standard treatment has failed.

Children with MIS-C after COVID

Who
Hospitalised children with the rare post-COVID inflammatory syndrome, alongside standard care.
Evidence
One 12-child placebo-controlled phase 2a trial and one earlier single case. Positive but far too small to prove benefit.
Route
Hospital-run trial, part funded by NIH

Source: Epocrates summary of Sci Transl Med, 2025-08

Long COVID

Who
People with long COVID, on the theory that a leaky gut lets viral protein keep entering the blood.
Evidence
No results yet. The MIS-C team says a long COVID trial is running.
Route
Clinical trial at the same hospital group

Source: Mass General Brigham, 2025-07

Celiac symptoms despite gluten-free diet

Who
Celiac patients who stay unwell on a strict gluten-free diet and have no approved drug.
Evidence
Phase 2 in 342 adults looked promising. Phase 3, planned for 525 patients, was stopped for futility at a 2022 interim look: the number of patients needed to show a difference from placebo was judged too large. No filing followed.

Source: Beyond Celiac, 2022-06

Legal last-resort routes

Expanded access (compassionate use)

For a serious or life-threatening condition with no comparable alternative and no trial you can join. Your physician asks the company for the drug, then files with FDA and an ethics board. The company can refuse. Costs are often not insured.

Source: FDA, expanded access for patients

Right to Try

For a life-threatening condition after approved options are exhausted and no trial is open to you. The drug must have finished Phase 1 and be in active development. Your doctor asks the manufacturer directly. FDA does not review requests.

Source: FDA, Right to Try

Trial finders

Search ClinicalTrials.gov by condition or drug name, check eligibility and call the listed site. ResearchMatch is a free NIH-funded registry that lets researchers find you. Discuss risks with your own clinician before enrolling.

Source: NIH, finding a clinical trial

Personal import for serious conditions

FDA may not object when a US citizen imports up to about three months of a drug for a serious condition with no effective US treatment, with written personal-use confirmation and a US doctor's details. It is discretion, not a right.

Source: FDA, personal importation

Patient-specific compounding

When the approved product cannot meet a specific need of an identified patient, a prescriber can order a compounded version from a licensed pharmacy. Lower price alone does not qualify. Ingredients must be pharmaceutical grade.

Source: Oregon Board of Pharmacy, Feb 2025

Amino-acid sequence

Water-avoidingWater-lovingStructural

Questions people ask

Does larazotide work for celiac disease?

In phase 2, only the lowest of three doses beat placebo. The phase 3 trial stopped in June 2022 after an interim look showed it would need far more patients to have a chance of success.

Does larazotide help leaky gut?

Leaky gut is not a recognized diagnosis, and larazotide has not been tested for it in a trial.

Is larazotide approved?

No, it is not approved anywhere, and it should not be relied on in place of a gluten-free diet.

Is larazotide safe?

Side effects matched placebo in the trials.

Your notebook

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Sources

  1. Leffler et al. 2015: larazotide in celiac disease, phase 2b
  2. 9 Meters Biopharma: phase 3 trial discontinued (21 Jun 2022)

Structure: PubChem