Larazotide
Larazotide acetate (AT-1001, INN-202)
Synthetic 8-amino-acid peptide (Gly-Gly-Val-Leu-Val-Gln-Pro-Gly) derived from research on Vibrio cholerae zonula occludens toxin. Acts as a zonulin receptor antagonist and tight junction regulator: closes 'leaky' intestinal tight junctions to reduce paracellular permeability. Originally developed for celiac disease (as adjunct to gluten-free diet). IMPORTANT: 9 Meters Biopharma's CeDLara phase 3 trial was DISCONTINUED in June 2022 for futility: the pivotal trial failed to meet its primary endpoint. Despite the failed phase 3, larazotide remains in active biohacker community use for 'leaky gut' and IBD-adjacent symptoms; sourced from research-peptide vendors as oral tablets / capsules.
At a glance
- Routes
- Oral
- Vial sizes
- 0.25 mg · 0.5 mg · 1 mg
- Evidence base
- 3 studies 3 human
Mechanism
Antagonizes zonulin (haptoglobin-2 precursor) at the tight-junction receptor, preventing the occludin / ZO-1 / claudin-5 disassembly that opens paracellular gaps in the intestinal epithelium. Net effect: reduces intestinal permeability, decreases gluten-derived peptide and LPS translocation into the lamina propria, and dampens downstream cytokine activation. Acts locally in the gut lumen: minimal systemic absorption (<1%). Phase 2b at 0.5 mg TID reduced celiac symptoms vs placebo; phase 3 (CeDLara) failed to meet primary endpoint.
Dosing
Any amounts shown here are reported from published studies only. 3 of 3 catalogued studies involved human subjects. COMPOUND does not publish its own dosing guidance.
Where a study reports an amount, it appears in that study's entry below, attributed to the source.
Published evidence
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Human RCT 2022
CeDLara Phase 3 trial discontinued for futility
Pivotal phase 3 in 525 celiac patients failed to meet its primary endpoint at interim analysis. Trial discontinued June 2022. No follow-on commercial development.
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Human RCT 2015
Larazotide acetate for persistent symptoms of celiac disease despite a gluten-free diet: a randomized controlled trial
Phase 2b in 342 celiac patients on GFD with persistent symptoms. Larazotide 0.5 mg TID reduced CeD-PRO symptom score significantly vs placebo. Established the 0.5 mg pre-meal dose pattern. Best published efficacy data, though phase 3 later failed to replicate.
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Human RCT 2007
The safety, tolerance, pharmacokinetic and pharmacodynamic effects of single doses of AT-1001 in coeliac disease subjects
First human trial of larazotide. Established negligible systemic absorption, safety profile, and reduction in intestinal permeability after gluten challenge.
Reported side effects
- Headache
- Occasional Mild · Most common side effect in CeDLara phase 2/3 trials. Usually mild and self-limiting.
- Urinary tract infection
- Occasional Mild · Reported imbalance in trial. Mechanism unclear, may be incidental.
- Upper respiratory infection
- Occasional Mild · Trial-reported imbalance, possibly placebo-comparable.
- Flatulence / GI changes
- Occasional Mild · Mild, transient.
Storage
Cool dry place, original packaging, protect from moisture. Shelf-life 2 years.