Larazotide: Celiac Disease Trials and What They Found
Larazotide (larazotide acetate, also called AT-1001) is an eight amino acid peptide tested as a treatment for celiac disease. In a 2015 trial of 342 adults, only the lowest dose beat placebo. Its phase 3 trial, NCT03569007, is listed on ClinicalTrials.gov as terminated by the sponsor. No FDA label for it was found.
Sources: Trial registry record (phase 3). ClinicalTrials.gov NCT03569007, Study to Evaluate the Efficacy and Safety of Larazotide Acetate for the Relief of CeD Symptoms. Record updated 26 July 2022, retrieved October 2026. Supports: phase 3 purpose and status, terminated by sponsor; Human trial (randomized). Leffler DA et al. Larazotide acetate for persistent symptoms of celiac disease despite a gluten-free diet: a randomized controlled trial. Gastroenterology, June 2015. PMID 25683116. Supports: 342 adults, doses tested, 0.5 mg met the primary end point, 1 and 2 mg did not, safety comparable with placebo; Review. Slifer ZM et al. Larazotide acetate: a pharmacological peptide approach to tight junction regulation. American Journal of Physiology, Gastrointestinal and Liver Physiology, 1 June 2021. PMID 33881350. Supports: eight amino acid structure, zonulin antagonist mechanism, rodent and pig studies
Short answer
- What is larazotide?
- An eight amino acid peptide meant to tighten the seals between gut lining cells. It is thought to block zonulin.
- What was it for?
- Celiac disease. Trials tested it for symptoms that continue despite a gluten-free diet.
- What did the trials find?
- Mixed results. One dose beat placebo in a 2015 trial. A 2022 review of four trials found no significant difference on two efficacy endpoints for people on a gluten-free diet. Safety looked similar to placebo.
- Where does it stand now?
- The phase 3 trial is listed as terminated by the sponsor. No FDA label was found, so it is not an approved medicine.
Sources: Trial registry record (phase 3). ClinicalTrials.gov NCT03569007, Study to Evaluate the Efficacy and Safety of Larazotide Acetate for the Relief of CeD Symptoms. Record updated 26 July 2022, retrieved October 2026. Supports: phase 3 purpose and status, terminated by sponsor; Human trial (randomized). Leffler DA et al. Larazotide acetate for persistent symptoms of celiac disease despite a gluten-free diet: a randomized controlled trial. Gastroenterology, June 2015. PMID 25683116. Supports: 342 adults, doses tested, 0.5 mg met the primary end point, 1 and 2 mg did not, safety comparable with placebo; Review. Slifer ZM et al. Larazotide acetate: a pharmacological peptide approach to tight junction regulation. American Journal of Physiology, Gastrointestinal and Liver Physiology, 1 June 2021. PMID 33881350. Supports: eight amino acid structure, zonulin antagonist mechanism, rodent and pig studies; Review (meta-analysis of trials). Hoilat GJ et al. Larazotide acetate for treatment of celiac disease: A systematic review and meta-analysis of randomized controlled trials. Clinics and Research in Hepatology and Gastroenterology, January 2022. PMID 34339872. Supports: four trials, 626 patients, no significant difference on two efficacy endpoints for patients on a gluten-free diet, adverse events comparable
What Larazotide Is and How It Was Meant to Work
Larazotide acetate is a single chain peptide of eight amino acids. Researchers call it a tight junction regulator. Tight junctions are the seals between the cells that line the gut.
The idea was to keep those seals closed. Larazotide is thought to act as a zonulin antagonist. Zonulin is a signal that makes the gut barrier more leaky. Blocking it is meant to reduce that leak and restore the barrier.
Many people find larazotide while reading about "leaky gut". No human trial of larazotide for leaky gut in people without celiac disease was found. For the general topic, see our leaky gut guide.
The Larazotide Trials, in Order
Larazotide went from a small safety study in 2007 to a phase 3 trial that was terminated. The table lines up each human study with who was in it and what it reported.
| Year | Record | Who was studied | What it reported |
|---|---|---|---|
| 2007 | Proof of concept study (AT-1001) | People with celiac disease given gluten | Single 12 mg doses. No increase in adverse events compared with placebo. |
| 2015 | Randomized controlled trial | 342 adults with ongoing symptoms on a gluten-free diet | The 0.5 mg dose met the main goal. The 1 and 2 mg doses did no better than placebo. |
| 2022 | Systematic review and meta-analysis | Four randomized trials, 626 patients | In people on a gluten-free diet, no significant difference from placebo on two efficacy endpoints. |
| 2022 | NCT03569007, phase 3 | Adults with celiac disease and persistent symptoms | Listed on ClinicalTrials.gov as terminated by the sponsor. |
| 2025 | Phase 2a randomized trial | 12 children with post-COVID multisystem inflammatory syndrome | A small trial outside celiac disease. |
The phase 3 trial set out to test larazotide against placebo for the relief of persistent symptoms in adults with celiac disease. That was the same question the 2015 trial had asked. The 2015 trial authors noted that symptoms often return despite a gluten-free diet. They added that no approved or proven non-diet treatment was available.
Sources: Trial registry record (phase 3). ClinicalTrials.gov NCT03569007, Study to Evaluate the Efficacy and Safety of Larazotide Acetate for the Relief of CeD Symptoms. Record updated 26 July 2022, retrieved October 2026. Supports: phase 3 purpose and status, terminated by sponsor; Human trial (proof of concept). Paterson BM et al. The safety, tolerance, pharmacokinetic and pharmacodynamic effects of single doses of AT-1001 in coeliac disease subjects: a proof of concept study. Alimentary Pharmacology and Therapeutics, 1 September 2007. PMID 17697209. Supports: single 12 mg trial doses with gluten challenge; no increase in adverse events vs placebo; Human trial (randomized). Leffler DA et al. Larazotide acetate for persistent symptoms of celiac disease despite a gluten-free diet: a randomized controlled trial. Gastroenterology, June 2015. PMID 25683116. Supports: 342 adults, doses tested, 0.5 mg met the primary end point, 1 and 2 mg did not, safety comparable with placebo; Human trial (phase 2a). Yonker LM et al. Viral spike antigen clearance and augmented recovery in children with post-COVID multisystem inflammatory syndrome treated with larazotide. Science Translational Medicine, 30 July 2025. PMID 40737433. Supports: phase 2a trial in 12 children, median age 5.7 years; Review (meta-analysis of trials). Hoilat GJ et al. Larazotide acetate for treatment of celiac disease: A systematic review and meta-analysis of randomized controlled trials. Clinics and Research in Hepatology and Gastroenterology, January 2022. PMID 34339872. Supports: four trials, 626 patients, no significant difference on two efficacy endpoints for patients on a gluten-free diet, adverse events comparable
What the 342 Person Trial Found
The lowest dose worked best, and the higher doses did not beat placebo. This 2015 randomized trial enrolled 342 adults with celiac disease who still had symptoms on a gluten-free diet.
The 2015 randomized controlled trial (PubMed 25683116) tested larazotide acetate at:
0.5, 1, or 2 mg, 3 times daily
Disclaimer: these are trial doses from a research study, not label information and not a recommendation. Larazotide has no approved label or approved dose, and dose decisions belong with a licensed clinician.
- The main goal of the trial was met with the 0.5 mg dose, with fewer symptoms than placebo.
- The 1 and 2 mg doses were no different from placebo on any end point.
- Safety was comparable with placebo.
A pattern where only the lowest dose beats placebo makes the result harder to read. The earlier 2007 proof of concept study tested single 12 mg doses of AT-1001. It was given to people with celiac disease who were challenged with gluten, to check safety and tolerability. That too was a trial dose, not a recommendation.
Sources: Human trial (randomized). Leffler DA et al. Larazotide acetate for persistent symptoms of celiac disease despite a gluten-free diet: a randomized controlled trial. Gastroenterology, June 2015. PMID 25683116. Supports: 342 adults, doses tested, 0.5 mg met the primary end point, 1 and 2 mg did not, safety comparable with placebo; Human trial (proof of concept). Paterson BM et al. The safety, tolerance, pharmacokinetic and pharmacodynamic effects of single doses of AT-1001 in coeliac disease subjects: a proof of concept study. Alimentary Pharmacology and Therapeutics, 1 September 2007. PMID 17697209. Supports: single 12 mg trial doses with gluten challenge; no increase in adverse events vs placebo
Larazotide Dosage
Larazotide has no approved dose. The only doses on record come from two published trials. The 2007 proof of concept trial (PMID 17697209) and the 2015 randomized trial (PMID 25683116) tested:
2007: single 12 mg doses
2015: 0.5, 1, or 2 mg, 3 times daily
Disclaimer: these are trial doses from research studies, not label information and not a recommendation. Dose decisions belong with a licensed clinician.
Sources: Human trial (proof of concept). Paterson BM et al. The safety, tolerance, pharmacokinetic and pharmacodynamic effects of single doses of AT-1001 in coeliac disease subjects: a proof of concept study. Alimentary Pharmacology and Therapeutics, 1 September 2007. PMID 17697209. Supports: single 12 mg trial doses with gluten challenge; no increase in adverse events vs placebo; Human trial (randomized). Leffler DA et al. Larazotide acetate for persistent symptoms of celiac disease despite a gluten-free diet: a randomized controlled trial. Gastroenterology, June 2015. PMID 25683116. Supports: 342 adults, doses tested, 0.5 mg met the primary end point, 1 and 2 mg did not, safety comparable with placebo
Larazotide for Leaky Gut: Claimed vs Tested
Gut barrier benefits have been tested only in celiac disease trials and in animals. No human trial of larazotide for leaky gut in people without celiac disease was found. In celiac disease, one dose beat placebo in 2015. Pooled trials showed no significant difference on two efficacy endpoints. The animal studies covered pancreatitis, arthritis and gut injury.
Sources: Human trial (randomized). Leffler DA et al. Larazotide acetate for persistent symptoms of celiac disease despite a gluten-free diet: a randomized controlled trial. Gastroenterology, June 2015. PMID 25683116. Supports: 342 adults, doses tested, 0.5 mg met the primary end point, 1 and 2 mg did not, safety comparable with placebo; Animal study (rats). Karahan D et al. Ameliorative Effects of Larazotide Acetate on Intestinal Permeability and Bacterial Translocation in Acute Pancreatitis Model in Rats. Digestive Diseases and Sciences, April 2024. PMID 38441784. Supports: rat pancreatitis results; Review (meta-analysis of trials). Hoilat GJ et al. Larazotide acetate for treatment of celiac disease: A systematic review and meta-analysis of randomized controlled trials. Clinics and Research in Hepatology and Gastroenterology, January 2022. PMID 34339872. Supports: four trials, 626 patients, no significant difference on two efficacy endpoints for patients on a gluten-free diet, adverse events comparable; Review. Slifer ZM et al. Larazotide acetate: a pharmacological peptide approach to tight junction regulation. American Journal of Physiology, Gastrointestinal and Liver Physiology, 1 June 2021. PMID 33881350. Supports: eight amino acid structure, zonulin antagonist mechanism, rodent and pig studies
Where Larazotide Stands Now
Larazotide is not an approved medicine. No FDA label for it was found. ClinicalTrials.gov lists the phase 3 trial, NCT03569007, as terminated by the sponsor.
Why was larazotide discontinued?
The registry says only "terminated by Sponsor". It gives no other reason, and this page does not add one.
What the pooled data show
The 2022 review pooled four randomized trials with 626 patients. For patients on a gluten-free diet, it found no significant difference from placebo on two efficacy endpoints. A 2025 review of celiac treatments adds a wider point. No treatment has yet been conclusively proven to replace the gluten-free diet.
Price and where to buy
There is no official price, because it is not an approved medicine. In our sources, people received it only inside clinical trials. This page does not link to any seller.
Sources: Trial registry record (phase 3). ClinicalTrials.gov NCT03569007, Study to Evaluate the Efficacy and Safety of Larazotide Acetate for the Relief of CeD Symptoms. Record updated 26 July 2022, retrieved October 2026. Supports: phase 3 purpose and status, terminated by sponsor; Review (meta-analysis of trials). Hoilat GJ et al. Larazotide acetate for treatment of celiac disease: A systematic review and meta-analysis of randomized controlled trials. Clinics and Research in Hepatology and Gastroenterology, January 2022. PMID 34339872. Supports: four trials, 626 patients, no significant difference on two efficacy endpoints for patients on a gluten-free diet, adverse events comparable; Review. Girbal-González M et al. Is There a Future Without Gluten Restrictions for Celiac Patients? Update on Current Treatments. Nutrients, 15 September 2025. PMID 41010485. Supports: no treatment yet proven to replace the gluten-free diet
Side Effects in the Trials
Across the trials, larazotide looked about as safe as placebo. Three records say so in their own words:
- 2007 proof of concept study: compared to placebo, no increase in adverse events in patients given AT-1001.
- 2015 trial of 342 adults: safety was comparable with placebo.
- 2022 review of four trials: other adverse events were comparable between the larazotide and placebo groups.
These were monitored trials in adults with celiac disease. They do not tell you about long-term use, use outside a trial or use by people without celiac disease. There is no FDA label with a side effect list. For general risks of research peptides, see peptide side effects.
Sources: Human trial (proof of concept). Paterson BM et al. The safety, tolerance, pharmacokinetic and pharmacodynamic effects of single doses of AT-1001 in coeliac disease subjects: a proof of concept study. Alimentary Pharmacology and Therapeutics, 1 September 2007. PMID 17697209. Supports: single 12 mg trial doses with gluten challenge; no increase in adverse events vs placebo; Human trial (randomized). Leffler DA et al. Larazotide acetate for persistent symptoms of celiac disease despite a gluten-free diet: a randomized controlled trial. Gastroenterology, June 2015. PMID 25683116. Supports: 342 adults, doses tested, 0.5 mg met the primary end point, 1 and 2 mg did not, safety comparable with placebo; Review (meta-analysis of trials). Hoilat GJ et al. Larazotide acetate for treatment of celiac disease: A systematic review and meta-analysis of randomized controlled trials. Clinics and Research in Hepatology and Gastroenterology, January 2022. PMID 34339872. Supports: four trials, 626 patients, no significant difference on two efficacy endpoints for patients on a gluten-free diet, adverse events comparable
Larazotide Beyond Celiac Disease
Researchers have also tested larazotide in animals and in one small trial in children. None of this is approved use.
- Animals: a 2021 review describes rodent and pig studies, including arthritis in mice and gut injury from poor blood flow in pigs.
- Rats: in a 2024 model of acute pancreatitis, larazotide reduced gut leakiness and damage. Fewer rats had gut bacteria spread to other organs.
- Children: a 2025 phase 2a randomized, double-blind, placebo-controlled trial tested larazotide in 12 children. They had multisystem inflammatory syndrome after COVID (MIS-C), with a median age of 5.7 years.
Twelve children is a very small trial, and animal results often do not carry over to people. For other peptides discussed for the gut, see peptides for gut health.
Sources: Human trial (phase 2a). Yonker LM et al. Viral spike antigen clearance and augmented recovery in children with post-COVID multisystem inflammatory syndrome treated with larazotide. Science Translational Medicine, 30 July 2025. PMID 40737433. Supports: phase 2a trial in 12 children, median age 5.7 years; Animal study (rats). Karahan D et al. Ameliorative Effects of Larazotide Acetate on Intestinal Permeability and Bacterial Translocation in Acute Pancreatitis Model in Rats. Digestive Diseases and Sciences, April 2024. PMID 38441784. Supports: rat pancreatitis results; Review. Slifer ZM et al. Larazotide acetate: a pharmacological peptide approach to tight junction regulation. American Journal of Physiology, Gastrointestinal and Liver Physiology, 1 June 2021. PMID 33881350. Supports: eight amino acid structure, zonulin antagonist mechanism, rodent and pig studies
Common Questions
Why was larazotide discontinued?+
The only official record says this: ClinicalTrials.gov lists the phase 3 celiac trial, NCT03569007, as terminated by the sponsor. The registry gives no other reason. Earlier, a 2022 review of four trials found no significant difference from placebo on two efficacy endpoints in people on a gluten-free diet.
What are the common side effects of larazotide peptide?+
In the trials, side effects were about the same as placebo. The 2007 study found no increase in adverse events with AT-1001 (larazotide). The 342 person trial in 2015 said safety was comparable with placebo, and a 2022 review found other adverse events comparable between the groups.
What are the side effects of larazotide acetate?+
Larazotide acetate is the form used in the trials, so the answer is the same: trial reports describe safety similar to placebo. These were monitored trials in adults with celiac disease, and no approved label lists side effects, because larazotide has no FDA label.
How much is larazotide?+
There is no official price. Larazotide is not an approved medicine, no FDA label for it was found, and it is not sold by pharmacies as a treatment. The phase 3 trial is listed as terminated by the sponsor.
Where can I buy larazotide online?+
It is not available as an approved medicine anywhere in our sources, and this page does not point to sellers. Larazotide was tested only inside clinical trials, and its phase 3 celiac trial was terminated by the sponsor.
Is larazotide approved for celiac disease?+
No. No FDA label for larazotide was found. A 2025 review says no treatment has yet been conclusively proven to be an effective alternative to the gluten-free diet.
How does larazotide work?+
It is thought to block zonulin, a signal that makes the gut wall more leaky. Researchers call it a tight junction regulator, meant to help restore the gut barrier.
Sources: Trial registry record (phase 3). ClinicalTrials.gov NCT03569007, Study to Evaluate the Efficacy and Safety of Larazotide Acetate for the Relief of CeD Symptoms. Record updated 26 July 2022, retrieved October 2026. Supports: phase 3 purpose and status, terminated by sponsor; Human trial (proof of concept). Paterson BM et al. The safety, tolerance, pharmacokinetic and pharmacodynamic effects of single doses of AT-1001 in coeliac disease subjects: a proof of concept study. Alimentary Pharmacology and Therapeutics, 1 September 2007. PMID 17697209. Supports: single 12 mg trial doses with gluten challenge; no increase in adverse events vs placebo; Human trial (randomized). Leffler DA et al. Larazotide acetate for persistent symptoms of celiac disease despite a gluten-free diet: a randomized controlled trial. Gastroenterology, June 2015. PMID 25683116. Supports: 342 adults, doses tested, 0.5 mg met the primary end point, 1 and 2 mg did not, safety comparable with placebo; Review (meta-analysis of trials). Hoilat GJ et al. Larazotide acetate for treatment of celiac disease: A systematic review and meta-analysis of randomized controlled trials. Clinics and Research in Hepatology and Gastroenterology, January 2022. PMID 34339872. Supports: four trials, 626 patients, no significant difference on two efficacy endpoints for patients on a gluten-free diet, adverse events comparable; Review. Girbal-González M et al. Is There a Future Without Gluten Restrictions for Celiac Patients? Update on Current Treatments. Nutrients, 15 September 2025. PMID 41010485. Supports: no treatment yet proven to replace the gluten-free diet; Review. Slifer ZM et al. Larazotide acetate: a pharmacological peptide approach to tight junction regulation. American Journal of Physiology, Gastrointestinal and Liver Physiology, 1 June 2021. PMID 33881350. Supports: eight amino acid structure, zonulin antagonist mechanism, rodent and pig studies
Related reading
This guide is for educational purposes only and is not medical advice. It describes what published trials, reviews and the ClinicalTrials.gov registry report about larazotide. It is not an endorsement or an instruction to use any compound. Larazotide is not approved for any use. If you have celiac disease, talk to a qualified healthcare professional before making any decision about your health.