Larazotide acetate (AT-1001) is a synthetic peptide taken by mouth that was developed to tighten the junctions between cells in the gut lining. Its structure is derived from a protein made by the cholera bacterium. It was tested for celiac disease but is not approved anywhere we know of.
Also known as: AT-1001, larazotide acetate.
There is no approved larazotide product, so there are no label strengths. In the largest completed trial (Leffler 2015), adults with celiac disease took 0.5 mg, 1 mg or 2 mg three times a day for 12 weeks. An earlier safety study gave single 12 mg doses (Paterson 2007). These are trial protocols, not personalized advice; confirm any dosing with your prescriber.
Larazotide is not FDA approved. A phase 3 trial in celiac disease (NCT03569007, 307 people enrolled) was terminated by its sponsor, according to ClinicalTrials.gov.
In the 12-week phase 2 trial of 342 adults who still had symptoms on a gluten-free diet (Leffler 2015), 0.5 mg three times a day reduced symptoms more than placebo; 1 mg and 2 mg did no better than placebo, and safety was similar to placebo. A 2022 meta-analysis of four trials (626 people) found it helped symptoms during a gluten challenge but not on a gluten-free diet, and found no difference in a standard gut-permeability test (Hoilat 2022).
A small 2025 placebo-controlled trial in 12 children with MIS-C, an inflammatory illness after COVID-19, reported no larazotide-related side effects and faster recovery of gut symptoms (Yonker 2025).
We could not find a published human half-life for larazotide, so we do not list one. It is meant to act on the gut lining rather than in the blood.
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