Tight junction regulator · Also known as Larazotide acetate, AT-1001, INN-202
A synthetic eight-amino-acid peptide that regulates intestinal tight junctions by antagonizing zonulin. Developed as an adjunct to a gluten-free diet for people with celiac disease who continue to experience symptoms despite dietary compliance.
Larazotide was originally developed by Alba Therapeutics, then licensed to Innovate Biopharmaceuticals (later 9 Metres Biopharma). It is the first tight junction regulator to reach advanced clinical trials. While phase 2 results at the 0.5 mg dose showed significant symptom improvement in celiac patients, the phase 3 trial was discontinued in 2023 after an interim analysis suggested an impractically large sample size would be needed to demonstrate significance.
When gluten fragments reach the intestinal lining in people with celiac disease, they trigger the release of zonulin, a protein that opens the tight junctions between intestinal epithelial cells. This increased permeability allows gluten peptides to cross into the submucosa, where they activate an immune response that damages the intestinal villi.
Larazotide works by antagonizing zonulin and promoting tight junction assembly. It inhibits myosin light chain kinase, reducing tension on the actin filaments that anchor tight junctions. This helps keep the intestinal barrier intact, preventing gluten fragments from crossing into immune-active tissue. Because it acts locally in the gut lumen and has minimal systemic absorption, its safety profile has been consistently favorable across clinical trials.
0.5 mg three times daily
Taken 15 min before meals0.5 mg three times daily
12 weeks (trial duration)Most side effects tend to improve as your body adjusts.