Larazotide // Tight Junction Regulator
An 8-amino acid peptide that directly regulates zonulin signaling to restore intestinal barrier function — the most direct intervention for leaky gut available. Currently in Phase 3 clinical trials for celiac disease. Larazotide doesn't just reduce inflammation — it physically seals the tight junctions between intestinal epithelial cells.
Sealing the gut at the molecular level.
Intestinal permeability (leaky gut) is driven by zonulin — a protein that opens tight junctions between epithelial cells. Larazotide is a zonulin antagonist that blocks this signaling, keeping tight junctions sealed and preventing undigested proteins, toxins, and bacteria from crossing the gut barrier.
Three times daily, before meals.
Larazotide is taken orally before meals to be present in the gut lumen when food arrives and triggers zonulin release. The pre-meal timing is critical — it needs to block zonulin signaling before the permeability cascade starts.
Phase 3 celiac disease trials.
Larazotide acetate (AT-1001) was developed based on Dr. Alessio Fasano's discovery of zonulin — the endogenous protein that regulates intestinal permeability. This was a foundational finding in understanding leaky gut at the molecular level.
Phase 2 clinical trials in celiac disease patients demonstrated that larazotide significantly reduced GI symptoms and intestinal permeability markers compared to placebo, even with ongoing gluten exposure. The compound was well tolerated with minimal adverse events.
Phase 3 trials (CeDLara) continued to evaluate larazotide as an adjunct to gluten-free diet in celiac patients. While the primary endpoint focused on celiac-specific symptoms, the mechanism of action — tight junction regulation — has implications for any condition involving intestinal permeability including IBS, food sensitivities, and autoimmune conditions.
Gut barrier compounds.
| Compound | Mechanism | Target | Route | Status |
|---|---|---|---|---|
| Larazotide | Zonulin Antagonist | Tight Junctions | Oral luminal | Phase 3 |
| BPC-157 Oral | Growth Factors | Mucosal Healing | Oral | Research |
| KPV | NF-κB Suppression | Inflammation | Oral / SubQ | Research |
| Glutamine | Fuel/Repair | Enterocytes | Oral | Supplement |
What to watch for.
Larazotide's side effect profile is manageable with proper protocol adherence. Baseline blood work before starting and periodic monitoring during use is essential.
- Very well tolerated in clinical trials
- Headache (comparable to placebo rates)
- Upper respiratory tract infection (comparable to placebo)
- Nausea (mild, uncommon)
- Luminal action = minimal systemic effects
- No significant safety signals in Phase 2/3 data
- Zonulin levels (direct target marker)
- Lactulose/mannitol ratio (permeability test)
- Fecal calprotectin
- tTG-IgA (tissue transglutaminase — celiac marker)
- CRP / inflammatory markers
- Comprehensive metabolic panel
- KPV for combined barrier repair + anti-inflammation
- BPC-157 Oral for mucosal healing alongside barrier sealing
- All three (Larazotide + KPV + BPC-157 Oral) = complete gut protocol
- Gluten-free diet still essential for celiac patients
- Take before meals — timing is critical for luminal presence
- No known peptide interactions
- Store in cool, dry place
- Oral formulation — no reconstitution needed
- Protect from moisture and heat
- Follow manufacturer guidelines for capsule/tablet form
- Research-grade may require compounding
Compounds that complement Larazotide.
The first drug designed to seal leaky gut — and it works.
Larazotide is the most mechanistically targeted gut barrier compound in existence. It doesn't treat symptoms of leaky gut — it blocks the molecular mechanism (zonulin) that causes it. Phase 3 clinical trials for celiac disease represent the most advanced clinical validation of any intestinal permeability intervention. For anyone dealing with leaky gut, food sensitivities, or autoimmune conditions with a GI component, Larazotide addresses the root cause. Stack with KPV (inflammation) and BPC-157 Oral (mucosal healing) for the most comprehensive gut repair protocol available. Take before meals — timing is non-negotiable.
Our free Protocol Guide includes the complete Gut Repair Stack — Larazotide, KPV, and BPC-157 Oral with timing, permeability markers, and tracking templates.