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Tissue Repair & Recovery

Larazotide

Also known as Larazotide acetate · AT-1001 · INN-202 · CAS 881851-50-9

Clinically studiedOralInvestigational only; not approved by the FDA or any major regulator for any indication. It was developed as an investigational new drug (most recently by 9 Meters Biopharma, after Innovate Biopharmaceuticals) and had received FDA Fast Track designation for celiac disease, but its Phase 3 celiac program was discontinued in 2022 and no marketing approval exists. As an unapproved peptide it is not a recognized 503A/503B compounded therapy and is not a lawful dietary supplement; any non-trial "research chemical" sourcing falls outside an approved regulatory pathway. It is not specifically named on the WADA Prohibited List, but athletes should note that unapproved investigational substances can fall under the List's catch-all category for substances with no current approval for human therapeutic use.

Larazotide is a first-in-class synthetic octapeptide derived from the Vibrio cholerae zonula occludens toxin, designed to act as a tight-junction regulator within the intestinal lumen. It is reported to antagonize zonulin-driven increases in intestinal permeability and to promote the rearrangement of tight-junction proteins and actin filaments, with proposed involvement of myosin light-chain kinase inhibition, thereby reducing paracellular "leakiness" of the gut barrier. It acts locally and is thought to undergo minimal systemic absorption, being degraded by intestinal proteases. The most extensive research base is in celiac disease, where it advanced through Phase 2 trials and into a Phase 3 trial as an adjunct to a gluten-free diet, though that Phase 3 study was discontinued in 2022 after an interim analysis judged a clinical benefit unlikely to be demonstrable. It remains an investigational compound and has also been explored in early studies for other gut-barrier-related conditions.

Studied / used for

  • Investigated for celiac disease as an adjunct to a gluten-free diet
  • Studied for reducing gluten-triggered intestinal permeability ('leaky gut') changes
  • Studied as a tight-junction / intestinal barrier regulator
  • Investigated in a small early-phase (Phase 2a) randomized trial for multisystem inflammatory syndrome in children (MIS-C) related to COVID-19
  • Explored preclinically in other barrier-dysfunction and autoimmune-related contexts such as rheumatoid arthritis

Commonly reported side effects

  • Headache (the most commonly reported event in trials, with rates similar to placebo)
  • Fatigue
  • Gastrointestinal symptoms such as abdominal discomfort, bloating, or nausea
  • Upper respiratory / nasopharyngitis-type symptoms
Clinically studied. Supported by human clinical trials. This reflects the strength of the research base, not effectiveness or a recommendation.

Not medical advice.

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