Is larazotide acetate FDA-approved, and what does the research show?

What is larazotide acetate?

Larazotide acetate is a synthetic peptide, a short chain of eight amino acids, taken by mouth ¹, ³. Its structure was derived from a protein secreted by the cholera bacterium, and it was found by screening peptides related to that protein ³, ¹². It was developed for celiac disease, an autoimmune condition in which gluten triggers injury to the small intestine ³, ¹². No non-dietary treatment is approved for celiac disease, and a lifelong gluten-free diet is the cornerstone of care ³, ¹². The trials tested larazotide acetate as an addition to that diet, never a replacement ³, ¹².

The trial papers describe it as locally acting: it works in the gut and was not detected in the blood even after doses higher than the trial doses ³, ⁹. The company that was developing it, 9 Meters Biopharma, announced the discontinuation of its phase 3 trial in June 2022 ⁶, ¹³.

Is larazotide acetate FDA-approved?

Larazotide acetate is not FDA-approved: Drugs@FDA lists no approved larazotide product as of November 9, 2026 ⁵. It is an investigational drug whose phase 3 trial was stopped by its sponsor in 2022 ⁶, ². With no approved product there is no FDA label, and so none of the prescribing and safety information a label carries ⁵.

The company, 9 Meters Biopharma, said on June 21, 2022, that a pre-specified interim analysis of its phase 3 trial, CedLara, "does not support trial continuation" ⁶. An interim analysis is a look at the data partway through a trial. The company said an independent statistician re-estimated how many patients the trial would need ⁶. The company said it had determined, after consulting the statistician, that "the additional number of patients needed to determine a significant clinical outcome between placebo and larazotide is too large to support trial continuation" ⁶.

The company said in June 2022 that it would analyze the data further and that "engagement with FDA will determine further plans for larazotide for the treatment of celiac disease" ⁶. It said in March 2023 that it had decided to discontinue further development of larazotide for celiac disease, and it ceased operations in July 2023 ¹³, ¹⁴. ClinicalTrials.gov records the trial as "Trial terminated by Sponsor," with 307 participants enrolled, a completion date of July 21, 2022, and no results posted ². The company had planned 525 ⁶.

The company's annual report for 2021, filed in March 2022, says FDA "has granted larazotide Fast Track Designation" for celiac disease; that is the company's statement ¹⁵. FDA describes Fast Track as "a process designed to facilitate the development, and expedite the review of drugs to treat serious conditions and fill an unmet medical need" ¹⁶. A designation is not an approval, and the company's own filing says such designations "do not change the standards for approval" ¹⁵.

No opened source states a lawful route to obtain larazotide acetate outside a clinical trial. An investigational drug is one still under study ⁶, ².

See the FDA status of every peptide, updated weekly.

How does larazotide acetate work?

The cells lining the gut are held together by tight junctions, the seals between neighboring cells ¹. In celiac disease these seals are believed to loosen, letting fragments of gluten pass between the cells into the tissue beneath, where they set off the immune reaction ⁹. Larazotide acetate is described as a tight junction regulator: shown in cells, it prevents the junctions from opening ⁹, and it has been associated with rearrangement of the junction proteins ¹.

It is thought to act as a zonulin antagonist, blocking zonulin, a protein that loosens the junctions ¹. The same review links it to inhibition of myosin light chain kinase, an enzyme that puts tension on the filaments inside the cell ¹. These mechanisms are proposed; the 2021 review says the drug "is thought to" act this way ¹.

In two gluten-challenge trials, of 184 and 86 adults, and in the pooled analysis, a urine test of gut permeability, the lactulose-to-mannitol ratio, did not differ significantly from placebo ⁷, ⁸, ⁹. Studied in animals for its effect on the gut barrier, in mice with induced arthritis and pigs with intestinal injury from loss of blood flow ¹.

What does the research show?

Studied in people: a randomized, double-blind, placebo-controlled phase 2b trial, 342 adults with celiac disease symptomatic after a year or more on a gluten-free diet, symptom scores over 12 weeks ³. A phase 2b trial is a mid-stage trial that tests doses, and randomized, placebo-controlled means patients were assigned by chance to the drug or an inactive placebo ³. Double-blind means neither patients nor doctors knew who had which ³.

The lowest of three dose groups met the primary end point, the result the trial was built to measure, with fewer symptoms than placebo ³. The two higher dose groups "were no different than placebo for any end point," and the authors called the results "mixed" ³. The paper describes this as the largest clinical trial reported in celiac disease at the time ³.

Studied in people: a randomized, double-blind, placebo-controlled trial, 184 adults with celiac disease on a gluten-free diet who were given 2.7 grams of gluten a day for 6 weeks ⁸. The lowest dose group reported fewer gluten-induced symptoms than placebo ⁸. Antibodies against tissue transglutaminase, the blood marker used to detect celiac disease, rose less in all three larazotide groups than on placebo ⁸. The permeability test showed no significant difference ⁸.

Studied in people: a randomized, double-blind, placebo-controlled trial, 86 adults with celiac disease, with or without 2.4 grams of gluten a day for 14 days, permeability and symptoms ⁹. The permeability measurements "were highly variable" and showed no significant difference between larazotide acetate and placebo ⁹. Some lower doses appeared to limit the worsening of symptoms that gluten caused; the highest dose did not ⁹.

Studied in people: a randomized, double-blind, placebo-controlled inpatient study, 21 adults with celiac disease, single doses with gluten exposure ¹², ¹⁷. Permeability rose 70% in the placebo group after gluten and did not rise in the larazotide group ¹². Interferon-gamma, an inflammatory signal, rose in 4 of 7 placebo patients and 4 of 14 larazotide patients ¹².

A 2021 systematic review, a study that gathers every trial of a drug by a set method, pooled four randomized controlled trials, RCTs, in a meta-analysis, a combined count ⁷. By the review's count they held 626 patients, 465 on larazotide acetate and 161 on placebo ⁷. Permeability did not differ from placebo whether or not patients took gluten ⁷. Among patients given gluten, symptom scores improved more with larazotide acetate; among patients on a gluten-free diet alone, the pooled scores did not differ ⁷. The authors wrote that the drug "seems somehow superior to placebo" for symptoms during gluten challenge and that "additional RCTs are warranted" ⁷.

The phase 3 trial, 307 adults with celiac disease and persistent symptoms on a gluten-free diet, was to measure abdominal symptom scores over 12 weeks ⁶, ². It was stopped after the interim analysis and has no posted results ⁶, ². Beyond Celiac, a patient organization, wrote that CedLara "was the first and only clinical investigation for a celiac disease treatment to reach Phase 3" ¹⁸.

Outside celiac disease, a randomized, placebo-controlled phase 2a trial, an early mid-stage trial, added larazotide to standard care in 12 children hospitalized with MIS-C ¹⁰. MIS-C is a multisystem inflammatory syndrome that follows COVID-19 ¹⁰. It reported faster resolution of gut symptoms and faster clearance of viral spike protein from the blood ¹⁰. A registry record of a 12-child larazotide trial in MIS-C is marked terminated because cases declined ¹⁹.

A phase 2a trial in 107 children and adults with long COVID is recorded as completed in June 2026, with no results posted ¹¹. The celiac trials measured symptoms, a urine permeability test and antibodies ⁷, ³, ⁸, ⁹; none of them reported healing of the intestinal lining on biopsy ³, ⁹.

What are the side effects?

In the 342-adult phase 2b trial, the authors wrote that "safety was comparable with placebo" ³. Eleven patients in each of the four groups stopped during treatment; across the groups, 18 stopped for adverse events and 14 because they were unwilling to continue ³. In the 86-patient gluten-challenge trial, no serious adverse events occurred ⁹. Headache was the most common adverse event there, reported by 17 patients with no difference among groups, and urinary tract infection was next ⁹. Adverse events the investigators judged related to the drug occurred in 25.0% of patients on larazotide acetate and 26.9% on placebo ⁹.

In the 184-patient trial, adverse event rates were similar between larazotide acetate and placebo ⁸. In the 21-patient single-dose study, adverse events did not increase compared with placebo ¹², ¹⁷.

The 2021 review found that larazotide acetate reduced gluten-related diarrhea during gluten challenge and that other adverse events were comparable with placebo ⁷. In the 12 children with MIS-C, no larazotide-related adverse events were reported over 24 weeks of follow-up ¹⁰. The phase 3 trial included a 12-week safety phase after treatment, and its results have not been posted ⁶, ².

The phase 3 and phase 2b trials excluded people with refractory celiac disease or severe complications of celiac disease and people with other chronic active gastrointestinal disease ², ⁴. The phase 2b trial also excluded people with diabetes or another autoimmune disease that might interfere with the study ⁴.

In sport

WADA, the World Anti-Doping Agency, does not name larazotide acetate on its 2026 Prohibited List ²⁰. Neither AT-1001 nor zonulin appears in the list ²⁰. Section S0 of the list prohibits at all times "any pharmacological substance which is not addressed by any of the subsequent sections of the List and with no current approval by any governmental regulatory health authority for human therapeutic use (e.g. drugs under pre-clinical or clinical development or discontinued, designer drugs, substances approved only for veterinary use)" ²⁰. Only one regulator's record was read, FDA's, and it shows no approval ⁵; whether S0 covers larazotide acetate is left open.

What JumpstartMD offers

JumpstartMD does not prescribe larazotide acetate. Our peptide library covers it so you have the facts on its FDA status and the evidence, current as of November 10, 2026.

Ready to talk?

Book FREE Consultation

Share your details and a JumpstartMD team member will reach out shortly. Or call 408.478.3496 for your free, no-obligation consultation.

Share your details and a JumpstartMD team member will reach out when we open.

Disclaimer

Compounded medications are not FDA-approved, and FDA does not review their safety, effectiveness, or quality before they are marketed. A licensed clinician decides after an evaluation whether a peptide is appropriate for you, and not every patient will qualify.