Emerging Research

Larazotide for Leaky Gut: The Peptide Nobody Is Talking About

June 20, 2026 12 min read PeptideOnline Research Team

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If you follow gut health research, you’ve probably heard of BPC-157 and KPV. But there’s a peptide most guides skip entirely that may be the most mechanistically targeted compound for intestinal permeability ever studied: larazotide acetate (AT-1001). It’s the only peptide to reach Phase 2 clinical trials specifically for leaky gut — and the results were promising before the program stalled for reasons that had nothing to do with safety.

What Is Larazotide?

Larazotide acetate (AT-1001) is a synthetic octapeptide (8 amino acids) that was developed by Alba Therapeutics (later acquired by Innovate Biopharmaceuticals, now 9 Meters Biopharma) specifically to modulate intestinal permeability. Its mechanism is uniquely direct:

Mechanism of Action

Larazotide directly targets tight junction proteins (zonulin-occludin, claudin) in the intestinal epithelium. When gliadin (a component of gluten) triggers zonulin release, tight junctions open and intestinal permeability increases. Larazotide blocks this opening by preventing the rearrangement of tight junction proteins, effectively acting as a "tight junction stabilizer."

This is fundamentally different from BPC-157 (which promotes tissue repair and angiogenesis) or KPV (which reduces inflammation). Larazotide doesn’t heal damaged tissue or reduce inflammation — it prevents the permeability increase from happening in the first place.

Clinical Trial Evidence

Larazotide has the strongest human clinical trial data of any gut-targeted peptide:

Phase 2 Trial (Celiac Disease)

A randomized, double-blind, placebo-controlled Phase 2 trial in celiac disease patients demonstrated:

26% decrease in symptomatic days (P=0.017)
31% increase in improved symptom days (P=0.034)
The study was published and peer-reviewed (PMID: PMC4446229)
Larazotide was well-tolerated with a safety profile comparable to placebo

What Happened to Phase 3?

Phase 3 trials were initiated but ultimately discontinued due to enrollment challenges, not safety concerns. The business environment for celiac disease drugs is challenging (many patients simply avoid gluten rather than take medication), and the company underwent corporate restructuring. The science was never the problem.

Larazotide vs BPC-157 vs KPV

Feature	Larazotide	BPC-157	KPV
Primary Mechanism	Tight junction stabilization	Tissue repair + angiogenesis	Anti-inflammatory (alpha-MSH fragment)
Best For	Preventing permeability increase	Healing existing gut damage	Reducing gut inflammation
Human Trial Data	Phase 2 RCT (celiac disease)	Pilot studies, limited RCTs	Preclinical data primarily
Administration	Oral	Oral or injectable	Oral or injectable
Research Availability	Limited (specialty suppliers)	Widely available	Available from select vendors
Complementary?	Yes — prevents permeability while BPC-157 heals	Yes — heals while larazotide prevents	Yes — reduces inflammation from both angles

The Stack Approach: Why Combination May Be Optimal

The most evidence-supported approach for gut healing pairs compounds that address different layers of gut dysfunction:

Larazotide — prevents tight junction opening (stops the leak)
BPC-157 — repairs damaged mucosal tissue (heals existing damage)
KPV — reduces inflammatory cascade (calms the immune response)

Each targets a distinct mechanism without overlap or redundancy. For researchers studying intestinal permeability, this three-compound approach addresses the problem from prevention, repair, and anti-inflammatory angles simultaneously.

Availability and Sourcing

Larazotide is not as widely available as BPC-157 or KPV from standard research peptide suppliers. It remains primarily a research compound without an established commercial supply chain in the peptide vendor space. For the more commonly available gut peptides:

BioPure Peptides

Code: POWER

BPC-157 (oral and injectable) and KPV — the two most popular gut-healing peptides. Third-party tested.

Shop BPC-157 →Shop KPV →

Midwest Peptide

Code: POWER — 10% Off

BPC-157 with COAs on every page. Free shipping.

Shop BPC-157 →

Apollo Peptide Sciences

Verified COAs

BPC-157 with independent testing and Refersion tracking.

Shop BPC-157 →

Frequently Asked Questions

What is larazotide?

Larazotide acetate (AT-1001) is a synthetic octapeptide that directly stabilizes intestinal tight junctions, preventing the increase in gut permeability (leaky gut) triggered by substances like gliadin. It is the only peptide to reach Phase 2 clinical trials specifically for intestinal permeability.

Is larazotide FDA approved?

No. Larazotide completed Phase 2 clinical trials for celiac disease with positive results but Phase 3 was discontinued due to enrollment challenges, not safety concerns. It remains an investigational compound.

How is larazotide different from BPC-157?

Larazotide prevents tight junction opening (stops permeability from increasing), while BPC-157 repairs already-damaged gut tissue through angiogenesis and growth factor upregulation. They target different mechanisms and are potentially complementary.

Can you buy larazotide?

Larazotide is not widely available from standard research peptide suppliers. It remains primarily a specialty research compound. BPC-157 and KPV, which address gut healing through complementary mechanisms, are readily available from verified suppliers.

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