Clinical / Pharmaceutical

Larazotide

AT-1001 · Larazotide acetate · zonulin antagonist

Larazotide (AT-1001) is an ingenious, clinical-grade octapeptide that stands as the world's premiere tight-junction regulator. Built to combat the devastating autoimmune cascade of severe Celiac disease, it directly attacks the mechanical root cause of "leaky gut" syndrome. Rather than broadly suppressing the immune system, it acts as a molecular gatekeeper, physically slamming shut the intestinal barriers that gluten attempts to force open.

Not FDA-approved - research chemical

Reviewed by CalcMyPeptide Editorial Team

·Last updated: August 2026·Evidence: Low·1 peer-reviewed citation

Typical research dose

0.5-1 mg 3× daily (oral)

Frequency

3× daily (oral, before meals)

Half-life

Short (~minutes) - acts locally in gut lumen

Common vials

N/A (oral)

Molecular weight

~620 Da

Use-case scores

0–10 against the evidence we have, not a gym ranking. Hidden domains do not apply here.

Injury & tissue3/10
Celiac zonulin-pathway program did not become an approved drug. Not a leaky-gut supplement.

Compound card

Class: Tight-junction octapeptide (AT-1001; celiac development casualty)
Formula: C25H44N8O10·C2H4O2 (acetate salt)
Status: Not FDA-approved · research use

How it works

Larazotide acetate (AT-1001) is a tight junction regulator peptide that prevents the permeation of zonulin - the primary modulator of intestinal permeability - from opening tight junctions in the gut epithelium. In celiac disease and leaky gut syndromes, zonulin triggers paracellular permeability, allowing dietary antigens (including gliadin fragments) to cross the epithelial barrier and trigger immune responses. Larazotide competes with zonulin at tight junction receptors to maintain barrier integrity. Phase 2b trials in celiac disease showed significant reduction in gastrointestinal symptoms and mucosal permeability markers.

Source: PMID: 32784092 (Phase 3)

Research Use Cases

✓Celiac Disease / Gut Permeability: High
✓Leaky Gut (General): Emerging

Dosing

Phase	Dose	Frequency	Notes
Phase 2b Clinical Dose	0.5 - 2 mg	Three times daily (oral, with meals)	0.5 mg TID showed best benefit:risk ratio in celiac Phase 2b trial.

Administration

Route / form

Oral

Timing

Three times daily with meals.

Empty stomach?

No - Food timing is not critical.

Timeline

Weeks 1-4

Reduction in intestinal permeability markers (lactulose:mannitol ratio).

Months 2-6

Symptomatic improvement in GI symptoms for celiac disease patients.

Who it is for

Celiac Disease / Gut Permeability

High

Phase 2b evidence for reduction in gut permeability and celiac GI symptoms.

Leaky Gut (General)

Emerging

Mechanism supports research use for non-celiac intestinal permeability disorders.

Safety & Considerations

Oral research peptide. Not FDA-approved. Phase 2b showed good tolerability. Not a replacement for gluten-free diet in celiac. Phase 3 trials for celiac non-responsive disease have been initiated.

Regulatory & Legal Status

FDA Status (US)

Research Only

WADA Status (2026)

Not Listed

Not currently on the WADA 2026 Prohibited List. Policies may change - verify before competition.

Classification

Research Chemical

US Compounding: Not eligible / not available

⚠️ This information is for educational purposes only and may not reflect the most current regulatory updates. Always verify with official FDA, WADA, and jurisdiction-specific sources before use.

Limits of current evidence

This site will not treat celiac disease from a larazotide page.

Verdict

Larazotide was developed for celiac disease. That program did not deliver a US approval. It is not a gluten-free pill and not BPC-157.

Interactions & Contraindications

Oral research peptide. Not FDA-approved. Phase 2b showed good tolerability. Not a replacement for gluten-free diet in celiac. Phase 3 trials for celiac non-responsive disease have been initiated.

Frequently Asked Questions

Can larazotide be used for leaky gut outside of celiac disease?▼

It is being researched for multiple tight-junction disorders (IBD, NASH, COVID-related gut permeability). Celiac disease is the most studied indication. Off-label use exists but human evidence is Phase 2 only.

How is larazotide taken?▼

0.5-2 mg orally, three times daily with meals. It acts locally in the gut lumen - systemic absorption is minimal.

References

Kelly CP et al. “"Larazotide acetate for persistent symptoms of celiac disease despite a GFD".” Gastroenterology (2013). PMID: 23624108

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