Reviewed & approved by Dr. Nova Reyes · Last checked 2026-10-25. ← Back to Evidence Library
Larazotide: what the evidence says
At a glance
What it is: larazotide acetate (AT-1001), an 8-amino-acid peptide taken by mouth that was developed to tighten the junctions between gut lining cells, as a treatment for celiac disease. R1, R3 Gray-market sellers market it for "leaky gut."
What the evidence says: mixed. In a 342-person trial, only the lowest of three doses beat placebo on celiac symptoms; higher doses did not. R1 It did not measurably change gut permeability in trials. R2, R3 A 12-child trial in post-COVID inflammatory syndrome (MIS-C) reported faster recovery. R4 A phase 3 celiac trial (NCT03569007) was terminated by its sponsor in 2022; its results have not been published in a peer-reviewed journal. R5, R6
Biggest risks: it was well tolerated in trials; headache and urinary tract infection were the most common side effects in one trial. R2 Gray-market products add quality risks.
Rating
| Human Human evidence | Limited (mixed results) for celiac symptoms R1–R3; Very limited for MIS-C (12 children) R4; No human data for "leaky gut" use |
| Animal Animal / lab evidence | Reported (not reviewed for this page) |
| Regulatory | Not FDA-approved (no Drugs@FDA entry found) R7 · WADA: not named; S0 likely applies as an unapproved drug UNVERIFIED |
| Established human dose | None. Study details lists what trials used |
Evidence verdict: Celiac disease: Limited · "Leaky gut" use: No human data Card verdict: Limited (celiac disease symptoms, mixed results) · "Leaky gut" use: No human data Card note: Varies by use, see page.
This page reports what studies used. It is not dosing advice.
Legend: HUMAN data · ANIMAL / LAB data · UNKNOWN · UNVERIFIED: not yet confirmed against a primary source
What is it?
Larazotide is a synthetic 8-amino-acid peptide. It was designed to block zonulin, a protein linked to loosening of the gut lining, so that gluten fragments cross the gut wall less easily in people with celiac disease. R2, R3
Does it work?
- Human Celiac symptoms despite a gluten-free diet: 342 adults, 12 weeks: the lowest dose reduced symptoms vs placebo; the two higher doses did not (see Study details). The authors call the results "mixed." R1
- Human Gluten challenge: 86 patients: no clear effect on permeability (measurements were highly variable); some lower doses limited symptom worsening. R2
- Human Meta-analysis: 4 RCTs, 626 patients: no difference in permeability; symptom benefit only during gluten challenge, not on a gluten-free diet alone. R3
- Human MIS-C (post-COVID) in children: 12 children, phase 2a: faster resolution of GI symptoms and faster spike-antigen clearance. R4
- 📋 Phase 3 (CedLara, NCT03569007; registry / company statement, not peer-reviewed): the registry lists it as terminated by the sponsor, with 307 people enrolled. R5 The company said an interim analysis of about half the planned enrollment found that the number of extra patients needed to detect an effect was too large to continue. R6 No results are published in PubMed, so this page draws no conclusion about how well it worked from the halt.
- Unknown "Leaky gut" in people without celiac disease: no studies found.
Is it safe?
- Human Generally well tolerated; no serious adverse events in the gluten-challenge trial; headache and urinary tract infection most common. R2
- Human Adverse events similar to placebo across 4 RCTs. R3
- Human No larazotide-related adverse events in 12 children. R4
- Unknown Long-term effects unknown.
Gray-market "research use only" Larazotide: extra risks
Unknown contents. Vials or capsules sold online as "research use only" are not made under drug-quality rules, so identity, strength and sterility are unknown. This is a general caution; we have not found independent testing data for this product. Unknown Vendor claims about effects in people are marketing, not evidence. Unknown
What we don't know
- Unknown Whether it helps celiac disease: the phase 3 results have not been published R5, R6
- Unknown Whether it does anything for "leaky gut" outside celiac disease
- Unknown What is in a gray-market product sold under this name
Is it legal?
US: not FDA-approved; no application found in Drugs@FDA data (Oct 25, 2026). R7 EU, UK and others: UNVERIFIED. WADA: not named on the 2026 List; S0 (non-approved substances) would apply if it has no approval anywhere, which we believe but have not verified UNVERIFIED.
Study details
These are amounts researchers used, not recommendations.
R1 Human RCT: celiac symptoms on a gluten-free diet (Leffler 2015)
| Study | People / model | Route | Amount used | Follow-up | Reported | Side effects / limitations | Citation |
|---|---|---|---|---|---|---|---|
| Leffler 2015 | 342 adults with celiac disease, symptomatic on a gluten-free diet | Oral | 0.5, 1 or 2 mg three times daily | 12 weeks treatment plus 4-week run-out | Only 0.5 mg met primary endpoint | Mixed dose response; sponsor-run | PMID 25683116 |
R2 Human RCT: gluten challenge (Leffler 2012)
| Study | People / model | Route | Amount used | Follow-up | Reported | Side effects / limitations | Citation |
|---|---|---|---|---|---|---|---|
| Leffler 2012 | 86 patients with diet-controlled celiac disease | Oral | 0.25, 1, 4 or 8 mg three times daily, with or without 2.4 g/day gluten | 14 days | No permeability difference; symptoms limited at some lower doses | Permeability test unreliable outpatient | PMID 22825365 |
R3 Human Meta-analysis (Hoilat 2022)
| Study | People / model | Route | Amount used | Follow-up | Reported | Side effects / limitations | Citation |
|---|---|---|---|---|---|---|---|
| Hoilat 2022 | 4 RCTs, 626 patients | Oral | Varied | Trial-dependent | No permeability difference; symptom benefit under gluten challenge only | Few trials | PMID 34339872 |
R4 Human RCT phase 2a: MIS-C in children (Yonker 2025)
| Study | People / model | Route | Amount used | Follow-up | Reported | Side effects / limitations | Citation |
|---|---|---|---|---|---|---|---|
| Yonker 2025 | 12 hospitalized children with MIS-C | Oral | Four times daily for 3 weeks (amount not in abstract) | 24 weeks | Faster GI recovery and spike clearance | Very small | PMID 40737433 |
R5–R6 📋 Phase 3 CedLara (registry / company statement, not peer-reviewed)
| Study | People / model | Route | Amount used | Follow-up | Reported | Side effects / limitations | Citation |
|---|---|---|---|---|---|---|---|
| CedLara (NCT03569007) | 307 adults with celiac disease on a gluten-free diet (registry, actual) | Oral | Planned arms: 0.25 mg or 0.5 mg vs placebo (company statement) | 12-week double-blind phase planned | Terminated by sponsor after interim analysis | Registry / company statement, not peer-reviewed; no published results | NCT03569007; company statement |
Full reference list (PubMed entries checked Oct 25, 2026)
- R1 Leffler DA, et al. Larazotide acetate for persistent symptoms of celiac disease despite a gluten-free diet: a randomized controlled trial. Gastroenterology. 2015. PMID 25683116
- R2 Leffler DA, et al. A randomized, double-blind study of larazotide acetate to prevent the activation of celiac disease during gluten challenge. Am J Gastroenterol. 2012. PMID 22825365
- R3 Hoilat GJ, et al. Larazotide acetate for treatment of celiac disease: A systematic review and meta-analysis of randomized controlled trials. Clin Res Hepatol Gastroenterol. 2022. PMID 34339872
- R4 Yonker LM, et al. Viral spike antigen clearance and augmented recovery in children with post-COVID multisystem inflammatory syndrome treated with larazotide. Sci Transl Med. 2025. PMID 40737433
- R5 ClinicalTrials.gov. NCT03569007: Study to Evaluate the Efficacy and Safety of Larazotide Acetate for the Relief of CeD Symptoms (phase 3, 9 Meters Biopharma). Status: Terminated ("Trial terminated by Sponsor"); enrollment 307 (actual); completed 2022-07-21. Checked Oct 25, 2026. https://clinicaltrials.gov/study/NCT03569007 (registry, not peer-reviewed)
- R6 9 Meters Biopharma. "9 Meters Biopharma Announces Interim Analysis of Phase 3 Study of Larazotide for Celiac Disease Does Not Support Trial Continuation." Press release, June 21, 2022 (SEC Form 8-K exhibit 99.1). https://www.sec.gov/Archives/edgar/data/1551986/000155198622000046/ex-991pressreleasedated621.htm (company statement, not peer-reviewed)
- R7 FDA. Drugs@FDA data (openFDA drugsfda endpoint), searched "larazotide" Oct 25, 2026: no application found. https://api.fda.gov/drug/drugsfda.json?search=products.active_ingredients.name:larazotide · Drugs@FDA: https://www.accessdata.fda.gov/scripts/cder/daf/ (a no-match search; Orange Book not separately checked)
Disclaimer
This page is for education and harm reduction, not medical advice or a recommendation to use Larazotide. Talk to a clinician you trust before using any drug, and report problems to FDA MedWatch (https://www.fda.gov/safety/medwatch).
Approved for Adam Greene by Dr. Nova Reyes, 2026-10-25.