Section 1 of 8Overview
Overview
Larazotide acetate is a synthetic eight-amino-acid peptide developed as an oral, locally acting regulator of intestinal epithelial tight junctions. It has been studied mainly as an adjunct to a gluten-free diet in celiac disease. Human research produced some symptom signals, but the programme did not establish an approved therapy: the phase 3 celiac trial was terminated in 2022.
Investigational, not an established celiac treatment
Early symptom signals must be read together with failed or variable permeability endpoints, non-responsive higher-dose arms and the terminated phase 3 programme.
Section 2 of 8Identity and nomenclature
Identity and nomenclature
| Property | Verified value |
|---|---|
| Preferred substance name | Larazotide acetate |
| FDA UNII | FO8S2IW40N |
| PubChem CID | 44146842 |
| Sequence | GGVLVQPG |
| Molecular formula | C34H59N9O12 |
| Molecular weight | 785.9 g/mol |
| CAS number | 881851-50-9 |
The imported PeptideGuide value of 899 g/mol was rejected because it conflicts with the PubChem record for the acetate salt.
The alias AT-1001 is context-dependent. FDA’s substance record maps it to larazotide acetate, but ClinicalTrials.gov record NCT00304512 uses AT1001 for migalastat hydrochloride. The code alone must therefore never be used to merge identities, evidence or safety data.
Section 3 of 8Proposed mechanism
Proposed mechanism
Cell models report that larazotide can promote tight-junction assembly, rearrange actin and redistribute junction proteins such as ZO-1, occludin and claudins. Reviews also describe zonulin antagonism and reduced myosin-light-chain phosphorylation as possible mechanisms.
These findings support a locally acting tight-junction-regulator hypothesis. They do not prove that a specific receptor mechanism or meaningful barrier restoration occurs in patients, and they do not validate the broad commercial phrase “leaky gut treatment.”
Section 4 of 8Phase 2 evidence in celiac disease
Phase 2 evidence in celiac disease
An 86-participant randomized gluten-challenge study found no significant treatment effect on its lactulose-to-mannitol permeability endpoint. The measure was highly variable, while some lower-dose groups showed exploratory symptom signals. The study reported no serious adverse events, but its size and duration cannot establish long-term safety.
NCT01396213 randomized 342 adults with persistent celiac symptoms despite a gluten-free diet. The 0.5 mg three-times-daily arm met the primary symptom endpoint, while the 1 mg and 2 mg arms did not differ from placebo. The mixed, non-monotonic pattern argues against treating the tested exposure as an established regimen.
A 2022 meta-analysis combined four randomized trials with 626 participants. It found no significant benefit on the lactulose-to-mannitol endpoint. Symptom improvement appeared in the gluten-challenge subgroup, but not in the subgroup already following a gluten-free diet.
Section 5 of 8Phase 3 outcome
Phase 3 outcome
NCT03569007 was a randomized phase 3 celiac study that enrolled 307 participants. ClinicalTrials.gov lists it as terminated, with “Trial terminated by Sponsor” as the stated reason and no results posted.
The sponsor’s SEC-filed June 2022 announcement adds the relevant context: a prespecified interim analysis indicated that the additional sample required to detect a statistically significant clinical effect would be too large to support continuation. No phase 3 efficacy claim can be made from an unpublished, terminated programme.
Section 6 of 8Other current research
Other current research
NCT05747534 is a separate phase 2 study of larazotide acetate in long COVID. The registry marked it active but not recruiting, with 107 actual participants, in its May 2026 verification. No results are posted. This shows continuing investigation in another condition; it does not establish benefit for long COVID or celiac disease.
Section 7 of 8Safety and dosing boundary
Safety and dosing boundary
Earlier phase 2 celiac trials generally reported adverse-event rates similar to placebo, but the reviewed studies were not sufficient to establish long-term safety, uncommon harms, interaction risk, reproductive safety or safety across other populations. The celiac phase 3 record has no posted results, and the active long-COVID study also has no posted results.
PeptideGuide’s “green” safety colour, one-hour half-life, laboratory suggestions and self-use dosing were not adopted. Trial doses document what researchers tested; they are not a regulator-approved regimen or treatment recommendation.
No established clinical regimen
This page does not convert trial exposures into self-use guidance. Celiac disease still requires qualified diagnosis and evidence-based clinical management.
Section 8 of 8Evidence conclusion
Evidence conclusion
Larazotide acetate has a verified octapeptide identity, a plausible local tight-junction research mechanism and real randomized human data. The decisive evidence is nevertheless mixed: permeability endpoints were inconsistent, only one lower-dose arm drove the strongest symptom signal, and phase 3 did not continue after interim analysis. It remains investigational, and claims of proven intestinal repair, general anti-inflammatory benefit or established dosing are not supported.