An 8-amino-acid oral peptide meant to tighten the gut lining in celiac disease. Its phase 3 trial was stopped in 2022 for lack of effect.
Also called Larazotide acetate, AT-1001, AT1001, INN-202, GGVLVQPG
When Larazotide's status or evidence changes, it's in the next morning's email.
Larazotide failed its only phase 3 trial: in June 2022 the sponsor stopped the celiac disease trial because interim results showed no significant benefit, and the drug is not approved anywhere. It is a short synthetic peptide, eight amino acids long (Gly-Gly-Val-Leu-Val-Gln-Pro-Gly), taken by mouth as a capsule. It was built to keep the tight junctions between gut lining cells closed. In celiac disease, gluten fragments slip through those junctions and set off the immune attack on the small intestine. Larazotide is described as a blocker of zonulin, a protein that opens the junctions, and it is meant to act inside the gut rather than in the bloodstream.
It was the first drug taken into a phase 3 trial for celiac disease. Four placebo-controlled phase 2 trials enrolled more than 600 people. In the largest, 342 adults who still had symptoms on a gluten-free diet took 0.5, 1 or 2 mg three times a day for 12 weeks. Only the lowest dose beat placebo on symptoms; the two higher doses did no better than placebo. None of the three larger phase 2 trials showed a change in gut permeability on the sugar absorption test the drug was designed to fix; only a 21-person single-dose safety study reported a difference.
The phase 3 trial, CeDLara, tested 0.25 mg and 0.5 mg three times a day. In June 2022 the sponsor, 9 Meters Biopharma, stopped it after an interim analysis: the results were not statistically significant, and an independent statistician estimated that too many extra patients would be needed to show a difference. Larazotide is not approved anywhere. Since then it has been tested at Massachusetts General Hospital in children with post-COVID multisystem inflammatory syndrome (MIS-C) and in a long COVID trial that finished in June 2026 without published results.
What it binds to, and what happens inside the body after that, step by step.
Larazotide is thought to block the zonulin pathway that loosens tight junctions between intestinal cells. In cell studies it stopped gliadin fragments and an opening peptide called AT-1002 from rearranging the junction protein ZO-1 and actin, and it cut how much of a gliadin fragment crossed a cell layer. Later work linked it to inhibition of myosin light chain kinase, which relaxes the tension that pulls junctions open. None of this has translated into a measurable change in gut permeability in the larger human trials.
Human results and animal results are kept apart below. A result in rats tells you a mechanism is plausible. It does not tell you what happens in a person.
The randomized trials of larazotide did not show a convincing benefit: its only phase 3 trial was stopped in 2022 because the interim results were not statistically significant, and it is not approved. The A grade reflects the number of human RCTs, not that the drug works: four phase 2 trials with 626 patients, the terminated phase 3 and a 12-child pediatric phase 2a. Symptom benefits appeared only at the lowest doses and not at higher ones, the intestinal permeability marker did not change in the larger trials, and the phase 3 trial was stopped because the effect was too small to detect. Safety has looked similar to placebo in every trial.
342 adults with celiac disease on a gluten-free diet for 12 months or more, still with symptoms
0.5 mg three times daily met the primary symptom endpoint (P = .022) and cut symptomatic days by 26%; the 1 mg and 2 mg doses were no different from placebo.
Read the study307 adults with celiac disease and symptoms on a gluten-free diet (525 planned), 0.25 mg or 0.5 mg three times daily vs placebo
Stopped in June 2022 after an interim analysis showed no statistically significant benefit and a re-estimate found too many extra patients would be needed.
Read the study184 adults with celiac disease eating 2.7 g of gluten daily for 6 weeks
1 mg three times daily limited gluten-induced symptoms (P = 0.002) and anti-transglutaminase antibody rises, but the lactulose/mannitol permeability ratio did not differ from placebo.
Read the study86 adults with diet-controlled celiac disease, 14 days with or without 2.4 g gluten daily
Permeability results were too variable to read; some lower doses appeared to limit symptom worsening, the 8 mg dose did not. Headache and urinary tract infection were the most common adverse events.
Read the study4 RCTs, 626 patients (465 larazotide, 161 placebo)
No effect on the lactulose/mannitol ratio. Symptoms improved during gluten challenge but not in patients on a gluten-free diet.
Read the study12 children with MIS-C, median age 5.7 years, phase 2a, added to standard care for 3 weeks
No larazotide-related adverse events; treated children cleared spike antigen and resolved gut symptoms faster than those on placebo. The trial was small and was stopped early as MIS-C cases declined.
Read the studyCaco-2 and IEC6 intestinal cell layers; gliadin-sensitized transgenic mice
Blocked gliadin- and AT-1002-induced ZO-1 and actin rearrangement and the drop in electrical resistance; preserved tight junction structure in mice.
Read the studyWhen a new Larazotide study in people is published, the daily email covers it.
These are questions the published research has not answered.
No product containing Larazotide is approved as a medicine by the FDA.
No regulator has approved larazotide. The phase 3 CeDLara trial (NCT03569007) was terminated by the sponsor after enrolling 307 of a planned 525 patients. Academic trials at Massachusetts General Hospital in MIS-C (NCT05022303, 12 children) and long COVID (NCT05747534, 107 people, completed June 2026) ran under FDA investigational rules. WADA does not name it, but S0 bans any drug with no government approval for human use, including drugs whose development was discontinued.
When the FDA or WADA changes Larazotide's status, it's in the next morning's email.
No human half-life has been published for Larazotide, so we do not draw a clearance curve. Half-lives quoted online for it are usually estimates from animal data.
This table records the doses that trials and approved labels used, with the source for each row. It is a record of research, not a recommendation, and it is open to free members.
Which symptoms are expected and which mean stop and get help: side effects and red flags.
Tap a claim to see what the studies found.
Every trial kept patients on a gluten-free diet or gave a small measured gluten challenge. It was developed as an add-on to the diet, and the phase 3 trial found no significant benefit.
The main permeability test, the urinary lactulose/mannitol ratio, did not change versus placebo in any of the phase 2 trials or in the pooled analysis of 626 patients. Only a 21-person single-dose safety study reported a difference.
In the 342-patient trial, 0.5 mg beat placebo but 1 mg and 2 mg did not. In the 2012 trial the 8 mg dose did not limit symptoms while some lower doses did.
The only phase 3 trial was terminated in 2022 and no new celiac trial has been registered since.
Supplied in trials as oral capsules. No published stability data for consumer storage.
Not applicable; it is taken by mouth.
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