Larazotide
Also known as: Larazotide acetate, AT-1001, INN-202
Larazotide is a research compound. It has been studied in human clinical trials for celiac disease but is not currently FDA-approved. For informational purposes only.
Overview
Larazotide (AT-1001) is a synthetic octapeptide that acts as a tight junction regulator — it competitively blocks zonulin, the primary physiological driver of intestinal permeability ('leaky gut'). It is one of the few compounds studied in human clinical trials specifically for tight junction dysfunction, with Phase 2 data in celiac disease demonstrating reduced intestinal permeability and symptom improvement even in the presence of ongoing gluten exposure.
Research Summary
Zonulin upregulation disrupts the tight junction proteins occludin and claudin, allowing paracellular passage of antigens, LPS, and inflammatory triggers into systemic circulation. Larazotide acts as a tight junction agonist by competitively displacing zonulin from its receptor and directly stabilizing tight junction complexes. The Phase 2b CeD trial (N=342) showed larazotide reduced the ratio of lactulose/mannitol (L/M ratio, standard intestinal permeability marker) and improved GI symptom scores versus placebo in actively-challenged celiac patients.
Dosing Range
low
0.25mg
moderate
0.5mg
high
1mg
Units: mg · Frequency: 3x daily (before meals)
Dosing ranges are aggregated from preclinical research and community protocols. Not medical dosing guidance.
Administration Routes
Reconstitution Notes
Primarily oral — capsule or powder dissolved in water taken before meals. For injectable research use: reconstitute with bacteriostatic water to 0.5mg/mL. Stable 28 days refrigerated.Step-by-step reconstitution guide →
Supplies you'll need
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Reported Side Effects
- Headache (most commonly reported adverse event in trials)
- Nausea (mild)
- Generally well-tolerated — adverse event rate similar to placebo in clinical trials
Research Papers
3 peer-reviewed sourcesCommunity Experiences
Aggregated from public forums. Anecdotal — not clinical evidence.
Community reports on larazotide for leaky gut, celiac-adjacent symptoms, autoimmune conditions, and gut dysbiosis.
View original threadCeliac community discussing AT-1001 trial results and research access options.
View original threadOverview
Intestinal permeability — the loosening of tight junctions between intestinal epithelial cells — underlies or contributes to an enormous range of conditions: celiac disease, Crohn's, IBS, food sensitivities, autoimmune diseases, and chronic systemic inflammation. Larazotide is one of the only compounds with Phase 2 human trial data specifically targeting this mechanism.
The Zonulin System
Tight junctions are the "gatekeepers" between intestinal cells. Zonulin — discovered by Alessio Fasano's lab — is the primary physiological regulator of these junctions. When zonulin is elevated (triggered by gliadin/gluten, dysbiosis, or stress), tight junctions open, allowing paracellular passage of:
- Undigested food antigens
- Bacterial LPS (endotoxin)
- Microbial fragments
- Inflammatory cytokines
This "leakage" into systemic circulation drives immune activation, contributing to autoimmune flares, food intolerances, and neuroinflammation.
How Larazotide Works
Larazotide does NOT block zonulin from being produced — it competitively occupies the zonulin receptor on tight junction complexes, preventing zonulin from binding and triggering junction opening. Additionally, it directly stabilizes occludin and ZO-1 (tight junction scaffold proteins) at the cell membrane.
The result: tighter junctions, reduced antigen translocation, lower systemic inflammatory load.
Clinical Trial Data
The most important data comes from CeD (Phase 2b) in celiac patients challenged with gluten:
- Larazotide 0.5mg 3x/day reduced L/M ratio (intestinal permeability marker) vs placebo
- Improved GI symptom response rate
- Well-tolerated — no significant safety signals
Phase 3 trials have been initiated and have stalled — ImmunGene (formerly Innovate Biopharmaceuticals) has not completed full Phase 3 enrollment, making this still a research compound.
Stacking Context
In research protocols, larazotide is often combined with:
- BPC-157 — systemic gut healing and angiogenesis
- KPV — mucosal anti-inflammatory
- Glutamine — tight junction substrate provision
- Probiotics — zonulin-modulating microbiome support
The combination targets gut permeability from multiple angles: structural (larazotide), anti-inflammatory (KPV), and regenerative (BPC-157).
Related Healing Peptides
BPC-157
HealingBody Protection Compound · PL 14736
BPC-157 is a synthetic pentadecapeptide derived from a protective protein found in gastric juice. It has been extensivel…
KPV
HealingLys-Pro-Val · Alpha-MSH C-terminal tripeptide
KPV is a C-terminal tripeptide fragment (Lys-Pro-Val) of alpha-melanocyte stimulating hormone (α-MSH). Despite its small…
LL-37
HealingCathelicidin LL-37 · hCAP-18 C-terminal fragment
LL-37 is the only human cathelicidin — a host defense peptide produced by neutrophils, epithelial cells, and macrophages…
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