Larazotide Protocol

Dosing & Research

Last Updated: September 4, 2026

Also known as: Larazotide Acetate, AT-1001

Chemical Identity

Amino Acid Sequence: Gly-Gly-Val-Leu-Val-Gln-Pro-Gly
Molecular Formula: C32H55N9O10 · C2H4O2 (acetate salt)
Molecular Weight: 785.89 (acetate salt) g/mol
CAS Number: 881851-50-9

Intestinal barrier / tight-junction research, Zonulin-antagonist pharmacology, Celiac disease and gluten-sensitivity models, Gut-permeability studies

Evidence Level

Human Clinical Data Available

Species Studied

Human • In vitro

Half-Life

Minimal systemic absorption reported; acts locally within the gut lumen

Administration

Oral

Frequency

Studied 3 Times Daily Before Meals In Clinical Trials

How It Works

Synthetic octapeptide (Gly-Gly-Val-Leu-Val-Gln-Pro-Gly) that antagonizes zonulin signaling, inhibiting zonulin-mediated tight-junction disassembly and reducing paracellular intestinal permeability. Acts locally in the gut rather than being absorbed systemically.
Intestinal barrier / tight-junction research
Zonulin-antagonist pharmacology
Celiac disease and gluten-sensitivity models
Gut-permeability studies

Dosing Structure

Dose

~0.5 mg (500 mcg) oral

Frequency

Studied 3 Times Daily Before Meals In Clinical Trials

Notes

Phase 2b randomized, double-blind, placebo-controlled trial (342 adults with celiac disease on a gluten-free diet for 12+ months) found 0.5 mg larazotide acetate three times daily reduced signs and symptoms versus a gluten-free diet alone (Leffler DA et al., 2015; PMID: 25683116). Studied as an adjunct to -- not a replacement for -- a gluten-free diet. Research and laboratory reference only -- not medical advice.

Example Protocols

Dose: ~0.5 mg (500 mcg) oral

Frequency: Studied 3 Times Daily Before Meals In Clinical Trials

Duration: Clinical trials conducted over 6-12 week treatment periods

Off Period: Not listed

Calculate dosing →

Find Research Grade Larazotide

Recommended vendors for sourcing research-grade material. PeptaBase does not sell peptides directly.

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COA Verified

Third-party COA-verified research peptides with published batch testing.

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Vendor Two Sciences

Purity Tested

US-based research compound supplier with independent purity testing.

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Bulk research peptide sourcing with batch-level documentation.

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View all recommended vendors →

Protocol Notes

•

Phase 2b randomized, double-blind, placebo-controlled trial (342 adults with celiac disease on a gluten-free diet for 12+ months) found 0.5 mg larazotide acetate three times daily reduced signs and symptoms versus a gluten-free diet alone (Leffler DA et al., 2015; PMID: 25683116).

•

Studied as an adjunct to -- not a replacement for -- a gluten-free diet.

•

Research and laboratory reference only -- not medical advice.

What Is Larazotide?

Larazotide acetate (AT-1001) is a synthetic octapeptide zonulin antagonist studied for intestinal barrier function and celiac disease. It acts locally in the gut lumen to block zonulin-mediated tight-junction disassembly, reducing intestinal permeability. Unlike most compounds on PeptaBase, larazotide has been through registered human Phase 2 clinical trials as an oral adjunct to a gluten-free diet, though it remains investigational and is not FDA-approved.

Research Observations - Not Medical Claims

▸Phase 2b trial (Gastroenterology, 2015; PMID: 25683116): In a multicenter, randomized, double-blind, placebo-controlled trial of 342 adults with celiac disease on a gluten-free diet for 12+ months, larazotide acetate 0.5 mg three times daily reduced signs and symptoms of celiac disease compared with a gluten-free diet plus placebo; higher tested doses (1 mg, 2 mg) did not outperform the 0.5 mg dose.
▸Mechanism studies: Larazotide antagonizes zonulin, a modulator of intercellular tight junctions, preventing zonulin-induced tight-junction disassembly and the resulting increase in paracellular gut permeability implicated in celiac disease and other gut-barrier research models.
▸Pharmacokinetics: Larazotide is designed to act locally within the intestinal lumen with minimal systemic absorption, distinguishing it from systemically absorbed peptide therapeutics.

Evidence Summary

Human Clinical Data AvailableInvestigational oral peptide; studied in registered Phase 2 clinical trials for celiac disease but not FDA-approved for any indication. For research and laboratory reference only -- no medical claims.

Evidence StrengthModerate