Larazotide: research
An oral gut-barrier peptide with mixed celiac results and a stopped phase 3 trial.
Also called: Larazotide acetate, AT-1001, AT1001, INN-202, NM-001.
Gut peptides · Oral tight-junction regulator; proposed zonulin-pathway antagonist.
13 primary human study records: 10 registries, one additional sponsor-listed phase 1 study and two compassionate-use reports. Several lack results; the celiac phase 3 trial stopped.
Studies
- First healthy-volunteer study (2005). pk-study, n=24, Healthy adults; CLIN1001-001. A sponsor filing documents 24 participants; detailed dose cohorts and results were not recovered. (source)
- First celiac proof-of-concept trial (2007). rct, n=21, Adults with controlled celiac disease given a single 2.5 g gluten challenge. A small inpatient study found less acute gut leak and fewer symptoms after gluten exposure. (source)
- Healthy volunteers: 10-day dosing. rct, n=24, Healthy adults aged 18–45; CLIN1001-003. The completed registry describes fixed cohorts; no tabulated results were posted. (source)
- Two-week gluten challenge (2012). rct, n=86, Adults with biopsy-confirmed celiac disease in remission on a gluten-free diet. The permeability endpoint failed; some lower-dose symptom results favored larazotide. (source)
- Six-week gluten challenge (2013). rct, n=184, Adults with well-controlled celiac disease on a gluten-free diet. The 1 mg arm reduced symptoms; none of the three doses improved the primary permeability test. (source)
- Active celiac disease: 8 weeks. rct, n=105, Adults aged 18–75 with active celiac disease and positive anti-tTG. This completed 105-person study has no posted results or recovered peer-reviewed report. (source)
- Six-week gluten challenge extension. rct, n=42, Adults with celiac disease on a gluten-free diet; CLIN1001-006 Part B. A separate 42-person extension was completed, but no results were posted. (source)
- Persistent celiac symptoms (2015). rct, n=342, Adults with celiac disease and symptoms despite a gluten-free diet for at least 12 months. 0.5 mg three times daily improved the primary symptom score; 1 and 2 mg did not. (source)
- CeDLara phase 3: stopped. rct, n=307, Adults with persistent celiac symptoms on a gluten-free diet. The phase 3 trial was terminated after interim analysis did not support continuation. (source)
- First MIS-C compassionate-use case (2021). case-report, n=1, A critically ill 17-month-old boy with MIS-C; one treated child within a 100-child mechanistic cohort. Antigen and inflammatory markers fell after larazotide was added; the single case cannot establish cause. (source)
- Four MIS-C compassionate-use cases (2022). case-series, n=26, Four children aged 3–17 versus 22 children receiving usual hospital care. Gut symptoms resolved sooner in four treated children; the comparison was not randomized. (source)
- MIS-C pilot randomized trial (2025). rct, n=12, 12 hospitalized children with MIS-C; median age 5.7 years. This small add-on trial reported faster recovery and no larazotide-related adverse events. (source)
- Long COVID: completed, results pending. rct, n=107, Children and adults aged 7–50 with long-COVID symptoms; actual enrollment 107. Completed on 2026-06-18; no posted results or peer-reviewed outcomes found by the review date. (source)
- Four celiac trials pooled (2022). meta-analysis, n=626, 626 patients across four published randomized celiac trials. Pooled trials did not show a permeability benefit; symptom results depended on gluten-challenge status. (source)
- Tight-junction assembly in cells (2012). in-vitro, MDCK and Caco-2 epithelial cell models. Larazotide promoted junction assembly and rearranged barrier proteins. (source)
- Gliadin barrier models (2012). animal, Caco-2 and IEC6 cells; gluten-sensitive HLA-transgenic mice. Larazotide preserved tight-junction structure in cell and mouse experiments. (source)
- Injured pig intestine (2021). animal, Ischemia-injured intestine from 6–8-week-old pigs, studied outside the body. 1 micromolar improved barrier recovery; higher concentration did not. (source)
- Histamine-challenged skin cells (2025). in-vitro, Cultured normal human skin cells, not treated patients. Larazotide reduced histamine-induced leak in cell layers; no MCAS clinical benefit was tested. (source)
Larazotide dosage
Typical reported dose: 0.25 mg three times a day before meals
- First celiac study: 12 mg: 12 mg per dose; Once daily once daily, by mouth. Studied in a trial. Studied in: Adults with controlled celiac disease. (source)
- Healthy volunteers: 0.25 mg: 0.25 mg per dose; Three times daily three times daily, by mouth. Studied in a trial. Studied in: Healthy adults aged 18–45. (source)
- Healthy volunteers: 1 mg: 1 mg per dose; Three times daily three times daily, by mouth. Studied in a trial. Studied in: Healthy adults aged 18–45. (source)
- Healthy volunteers: 4 mg: 4 mg per dose; Three times daily three times daily, by mouth. Studied in a trial. Studied in: Healthy adults aged 18–45. (source)
- Two-week gluten challenge: 0.25 mg: 0.25 mg per dose; Three times daily three times daily, by mouth. Studied in a trial. Studied in: Adults with celiac disease in remission. (source)
- Two-week gluten challenge: 1 mg: 1 mg per dose; Three times daily three times daily, by mouth. Studied in a trial. Studied in: Adults with celiac disease in remission. (source)
Highest studied: 8 mg orally three times daily in gluten-challenge trials; 24 mg total per day..
These are doses reported in labels, trials or user reports, not a personal plan. Check the source behind each one.
Larazotide side effects and risks
Reported side effects
- Headache: Six week trial: 1/4/8 mg, 7%/5%/12%; placebo 7%. All cause events, not proven drug effects., mild. Track persistent or worsening symptoms; review other causes. (source)
- Nausea: Six week trial: 1/4/8 mg, 10%/14%/9%; placebo 19%. Gluten challenge can cause the same symptoms., mild. Persistent vomiting or poor fluid intake needs clinical review. (source)
- Diarrhea: Six week trial: 1/4/8 mg, 17%/28%/19%; placebo 28%. These are all cause trial events., moderate. Track fluids and stools; blood, fainting or severe pain needs urgent care. (source)
- Bloating and gas: Six week trial: bloating 14%/12%/14%; gas 17%/14%/12% at 1/4/8 mg. Placebo: 19% and 14%., mild (source)
- Constipation: Six week trial: 1/4/8 mg, 12%/2%/16%; placebo 12%. Drug causation is uncertain., mild (source)
- Urinary infection: 14 day gluten challenge: 16.7%/8.3%/8.3%/8.3% at 0.25/1/4/8 mg; placebo 0%. Very small groups., moderate. Painful urination or fever needs assessment; a causal link is unproven. (source)
- Serious or delayed harm: No serious events in the 86 person trial; no drug related serious events in the 342 person trial. Long term rates are unknown., serious (source)
Stop and get help if
- Sudden severe abdominal pain, blood in vomit, or black or bloody stool: Get emergency assessment. Do not assume this is “gut healing” or a routine peptide effect.
- Throat or tongue swelling, trouble breathing, collapse or fainting after a dose: Call emergency services; use prescribed emergency adrenaline if available.
- Ongoing diarrhea, unexplained weight loss or persistent celiac symptoms: Arrange prompt assessment for gluten exposure, nutrient loss and other bowel disease.
Who should avoid it
- pregnant: No pregnancy safety data; celiac trials excluded pregnancy. This is a precaution, not a demonstrated fetal risk.
- breastfeeding: No milk-transfer or infant-safety data; breastfeeding participants were excluded from celiac trials.
- tryingToConceive: Reproductive safety is unknown. Celiac trials required contraception for participants who could become pregnant.
- under18: No routine pediatric regimen is established. Small MIS-C studies used hospital research or emergency access.
- other: Avoid a known allergy trigger; larazotide-specific allergy rates are unknown.
- kidneyDisease: No dedicated kidney-disease dose study found; oral trial safety does not establish dosing in severe kidney disease.
- liverDisease: No dedicated liver-disease dose study found; clinically important illness was excluded from celiac trials.
- other: Persistent symptoms need a cause-specific workup. Refractory disease and severe celiac complications were excluded from the main trial.
- testedAthlete: S0 inference: an unapproved investigational drug is prohibited at all times under the 2026 list; larazotide is not named individually.
Interactions
- Proton pump inhibitors and other acid-reducing drugs: Drugs changing gut pH were excluded from celiac trials. Effects on capsule release or drug absorption have not been measured.
- NSAID pain relievers: Regular NSAID use was excluded because it can affect gut measures. A harmful interaction with larazotide has not been shown.
- Immunosuppressants, corticosteroids and IVIG: Excluded from celiac trials, but steroids and IVIG were used in small MIS-C studies. Safety of other combinations is unknown.
- Other experimental gut peptides: Reported blends have no verified combination trial. Duplicate larazotide can hide the total daily dose.
Product quality risks
- No independent larazotide-specific market survey of purity, dose or sterility was found.
- FDA cited larazotide acetate among ineligible compounding ingredients in a 2025 supplier warning letter.
- General peptide alerts describe wrong ingredients, too much or too little drug, contamination and nonsterile injections. These are not larazotide-specific rates.
- An HPLC purity percentage does not establish identity, dose, sterility or gut-release performance.
How Larazotide works
It acts inside the gut, where it may help keep the seals between lining cells closed. Cell studies show changes in the proteins that form these seals. The exact receptor mechanism is still debated.
- Tight-junction proteins and actin: Promotes assembly of the seals between gut-lining cells in laboratory models.
- Proposed zonulin/PAR2 pathway: May reduce signals that loosen the gut barrier; the precise molecular target is not settled.
Half-life: Human blood half-life is not established; drug levels were too low to quantify in oral trials.
Gaps: Phase 3 stopped; no public per-arm phase 3 efficacy or safety tables were found. Long-COVID trial completed in June 2026 with 107 participants; no posted results or publication found. No controlled evidence for nonspecific “leaky gut,” MCAS or community peptide combinations. No dedicated interaction studies with insulin, sulfonylureas, anticoagulants or narrow-window oral medicines were found. No reproductive, long-term cancer, severe kidney/liver disease or chronic pediatric safety program was identified. No human injection, sublingual, nasal or topical regimen was established. The 36 mg healthy-volunteer dose appears in reviews; primary dose cohorts, timing and event tables were not recovered. 2015 detailed safety tables and 2025 MIS-C per-arm outcomes were inaccessible; missing numbers are not estimated. Commercial zonulin tests are not established here as a dosing target or proof of clinical recovery. International authorization, import and Australian scheduling details remain partly unverified. No verified vial-size, water-volume, storage or home-mixing protocol was found in eligible independent sources.
Related to Larazotide
- BPC-157: An experimental repair peptide with mostly animal evidence and a few small human reports.
- KPV: An alpha-MSH fragment studied for gut inflammation in animals, with no human dosing trial.
Sources
- 503B Bulk Drug Substances List, FDA · FDA · 2026
- Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the Federal Food, Drug, and Cosmetic Act, FDA · FDA · 2026
- Bulk Drug Substances Used in Compounding, FDA · 2026
- Medicines, European Medicines Agency · European Medicines Agency · 2026
- Peptide products, Therapeutic Goods Administration · TGA · 2026
- Pyrogen and Endotoxins Testing: Questions and Answers, FDA · 2026
- Risks of buying peptide products online, Therapeutic Goods Administration · 2026
- The 2026 Prohibited List, World Anti-Doping Agency · WADA · 2026
- Understanding the Risks of Compounded Drugs, FDA · 2026
- Bulk Drug Substances Nominated for Use in Compounding Under Section 503B of the Federal Food, Drug, and Cosmetic Act, FDA · FDA · 2025
- Darmerica, LLC - 716152 - 12/08/2025, FDA · FDA · 2025
- Supply unlicensed medicinal products (specials), MHRA · 2025
- American College of Gastroenterology Guidelines Update: Diagnosis and Management of Celiac Disease., Rubio-Tapia A et al. · The American journal of gastroenterology · 2023
- Anaphylaxis, NHS · NHS · 2023
- Stomach ache, NHS · 2023
Sources checked: 2026-10-18.
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