CalcMyPeptide
Clinical / PharmaceuticalAlso known as: AT-1001, Larazotide acetate, zonulin antagonist

Larazotide

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.

Reviewed by CalcMyPeptide Editorial Team
Last updated: April 2026Evidence: Emerging1 peer-reviewed citation

Quick Stats

Half-LifeShort (~minutes) — acts locally in gut lumen
Dose Range0.5-1 mg 3× daily (oral)
Frequency3× daily (oral, before meals)
Vial SizesN/A (oral)
BioavailabilityLocal (gut-acting) — minimal systemic absorption
Year Developed2004

Scientific Data

Molecular Formula
C25H44N8O10·C2H4O2 (acetate salt)
Molecular Weight
~620 Da

Mechanism of Action

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)

Dosing Protocol

Typical Dose0.5-1 mg 3× daily (oral)
Frequency3× daily (oral, before meals)
Half-Life~4-6 hours (estimated)

Dosing Protocols

Phase 2b Clinical Dose

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

Body-Weight Dosing Reference

Estimated doses extrapolated from the published research range of 5003000 mcg/day (referenced to 70 kg / 154 lb). These are approximations — consult a qualified healthcare provider for personalised guidance.

WeightLowTargetHigh
120 lb(54 kg)386 mcg1350 mcg2314 mcg
140 lb(63 kg)450 mcg1575 mcg2700 mcg
160 lb(73 kg)521 mcg1825 mcg3129 mcg
180 lb(82 kg)586 mcg2050 mcg3514 mcg
200 lb(91 kg)650 mcg2275 mcg3900 mcg
220 lb(100 kg)714 mcg2500 mcg4286 mcg
250 lb(113 kg)807 mcg2825 mcg4843 mcg

💉 For exact syringe units based on your vial concentration, use the Larazotide Reconstitution Calculator →

Administration

Route
Oral
Timing
Three times daily with meals.
Fasting Required?
No — food timing not critical

Expected 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 Is It 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.

Dosing Quick Reference

Larazotide— Dosing Guide
Dose Range
0.5-1 mg 3× daily (oral)
Half-Life
~4-6 hours (estimated)
Frequency
3× daily (oral, before meals)
Route
Oral
Clinical / Pharmaceuticalcalcmypeptide.com

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

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

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