VialOwlLibrary / Repair and recovery
Larazotide
Also known as Larazotide acetate, AT-1001, INN-202
Failed trials
Oral octapeptide designed to tighten junctions between gut lining cells. Studied for coeliac disease; the phase 3 trial was stopped in 2022 because it was unlikely to show a meaningful benefit.
Not an approved medicine. Larazotide is not an approved medicine for this use in Australia or the United States. This page summarises published research for information only. It is not a recommendation to use Larazotide, and VialOwl does not sell or supply it.
Background
An 8 amino acid oral peptide whose structure was derived from a protein made by the cholera bacterium (Vibrio cholerae zonula occludens toxin). It was developed by Alba Therapeutics, building on Alessio Fasano's zonulin research; the phase 3 coeliac disease trial was terminated by its sponsor in 2022.
How it is thought to work
Acts inside the gut to stop the tight junctions between lining cells from opening in response to gluten fragments and inflammatory signals, aiming to reduce how much gluten crosses the gut wall. It is described as a zonulin antagonist.
What is claimed, and the evidence
| Claim | Evidence | Notes |
|---|---|---|
| Reducing symptoms of coeliac disease alongside a gluten free diet | Human trials Mixed results | A 342 patient phase 2b trial met its primary endpoint only at the lowest dose (0.5 mg); higher doses did not differ from placebo. The phase 3 trial (307 enrolled) was terminated after an interim analysis. |
| Reducing gluten induced symptoms and immune response during gluten challenge | Human trials | Some benefit on symptoms and antibodies in a 184 patient trial, but no change in gut permeability tests. |
| Reducing gut permeability | Human trials Not supported | A meta-analysis of 4 trials found no significant difference from placebo on the lactulose to mannitol permeability test. |
| Treating 'leaky gut', inflammatory bowel disease or autoimmune disease | Animal studies only | Animal and laboratory studies; the leaky gut claim for general use is marketing. |
Side effects
| Effect | How often | Notes |
|---|---|---|
| Adverse events similar to placebo | Common | Across randomised trials, adverse event rates were comparable to placebo. |
| Gluten related diarrhoea (reduced rather than caused) | Frequency unknown | A meta-analysis found fewer gluten related diarrhoea events than placebo during gluten challenge; other adverse events were comparable. |
Warnings
- Not approved anywhere; development for coeliac disease was stopped after the phase 3 interim analysis.
- It does not replace a gluten free diet.
- Unapproved products bought online or from compounders may be contaminated, non sterile, underdosed, overdosed or contain a different substance; the TGA warns their labelling may be inaccurate and it has received reports of severe allergic reactions and hospitalisations.
Regulatory status
- Australia
- Not included on the ARTG (unapproved). Not specifically listed in the Poisons Standard (June 2026).
- United States
- Not FDA approved. The phase 3 coeliac disease trial was discontinued in 2022 after an interim analysis.
Sources
- PubMed: Larazotide acetate for persistent symptoms of celiac disease despite a gluten-free diet: a randomized controlled trial
- PubMed: Larazotide acetate for treatment of celiac disease: systematic review and meta-analysis
- PubMed: Larazotide acetate regulates epithelial tight junctions in vitro and in vivo
- ClinicalTrials.gov: NCT03569007, phase 3 larazotide acetate in coeliac disease (terminated)
- PubMed: Larazotide acetate in coeliac disease undergoing gluten challenge
Also in Repair and recovery
From the VialOwl library, reviewed 26 September 2026. For education and general information. It is not medical advice and not a recommendation to use Larazotide.