Larazotide Acetate
PeptideThe medical score (52) is substantially higher than the community score (28), as clinical Phase 2 RCTs [s4, s5, s6] demonstrate measurable efficacy in celiac disease, while the biohacking community has little experience with the compound and very few user reports exist [c1]. The discrepancy reflects the typical situation of an experimental peptide used predominantly in a clinical rather than a self-experimentation context.
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TL;DR
Larazotide acetate is the best-studied peptide for intestinal permeability regulation — four Phase 2 RCTs in celiac patients show consistent symptom reduction at 0.5 mg three times daily, with a clean safety profile so far. The critical caveat: the Phase 3 trial was discontinued, no regulatory approval exists, and outside clinical trials it's only available through grey-market suppliers of unknown quality. The biohacking community has barely noticed this compound — fewer than ten relevant posts exist, and the one concrete user report was negative. Anyone self-administering larazotide operates in a legal grey zone and assumes full quality risk.
Description
Synthetic octapeptide acting as a zonulin antagonist that stabilizes intestinal barrier function; investigated clinically primarily in celiac disease, not yet approved [s1, s2].
Larazotide acetate (AT-1001, INN-202) is a synthetic octapeptide originally derived from the zonula occludens toxin (ZOT) of the bacterium Vibrio cholerae [s2, s3]. It was initially developed at the University of Maryland and subsequently by Alba Therapeutics (founded by Alessio Fasano). Later development phases were conducted by Innovate Biopharmaceuticals and 9 Meters Biopharma, respectively [s3]. The compound is considered the first representative of a new class of tight junction regulators. Its primary area of clinical research was celiac disease (CeD): it was intended to alleviate persistent symptoms as an adjunct to a gluten-free diet (GFD) and to reduce gluten-induced intestinal damage [s4, s5]. Larazotide acetate was investigated in four randomized, placebo-controlled Phase 2 trials at various doses (0.5 mg, 1 mg, 2 mg, up to 8 mg daily) [s4, s5, s6]. The studies demonstrated good tolerability and a reduction in gastrointestinal symptoms, particularly at the low dose (0.5 mg three times daily). Improvements in the lactulose/mannitol ratio (LAMA ratio as a measure of intestinal permeability) were reproducible only under inpatient conditions [s5, s7]. A Phase 3 trial (NCT03569007) was terminated prematurely before an FDA approval application could be submitted [s8]. Preliminary pilot studies exist for other indications such as PIMS (Pediatric Inflammatory Multisystem Syndrome) [s9]. No EMA approval exists. Larazotide acetate is available on the grey market as a "research chemical," which is associated with considerable quality and safety risks [s10].
Legal Status (DE)
Larazotide acetate is not approved as a medicinal product in Germany or the EU. No EMA or BfArM approval exists. The compound is in the clinical development stage (Phase 2 completed, Phase 3 discontinued). Outside of clinical trials, it is classified in Germany as an unapproved research chemical; purchase and possession for personal use falls within a legal grey area [s1, s8].
Mechanism of Action
Larazotide acetate acts as an antagonist at the zonulin receptor. Zonulin is an endogenous protein released following intestinal gliadin exposure that triggers a signaling cascade leading to disassembly of tight junction proteins (including occludin, claudins, ZO-1) and opening of the paracellular pathway [s1, s2]. Larazotide acetate blocks this receptor, thereby preventing zonulin-mediated increases in intestinal permeability. In addition, the compound actively promotes reassembly of actin filaments and E-cadherin around the tight junctions, restoring epithelial barrier function [s1, s3]. Mechanistically, influences on the EGF receptor (EGFR) and protease-activated receptor 2 (PAR-2) are also under discussion [s3]. By stabilizing the intestinal barrier, translocation of gliadin peptides into the lamina propria and the resulting immune activation (anti-tTG antibodies, T-cell response) are reduced [s4, s5]. Since larazotide acetate is undetectable in human serum following oral administration even with highly sensitive assays, it apparently acts exclusively locally within the intestinal lumen without systemic absorption [s8].
Dosing
Symptomlinderung bei Zöliakie (Gluten-Challenge-Setting, klinische Studie)
- Dose
- 0.5 mg
- Frequency
- 3× täglich vor den Mahlzeiten
- Route
- oral
- Duration
- 12–26 Wochen (in Studien)
- Timing
- Take before meals
- With food
- vermeiden
Höhere Dosierungen (Phase-2-Exploration, nicht empfohlen)
- Dose
- 1 mg or 2 mg
- Frequency
- 3× täglich
- Route
- oral
- Duration
- 12 Wochen
- Timing
- Take before meals
- With food
- vermeiden
Doses of up to 8 mg/day were tested in clinical trials. The best efficacy was demonstrated at 0.5 mg three times daily [s5]. Dosages outside of clinical trials are undefined and not recommended due to lack of approval.
Larazotide acetate is not approved as a dietary supplement. Self-medication is not provided for in Germany. Products available outside of trials are declared as research chemicals and lack quality control [s10].
Calculate reconstitution, plan dosing, look up injection technique
Side Effects
| Side Effect | Frequency | Severity |
|---|---|---|
| Gastrointestinale Beschwerden (Übelkeit, Bauchschmerzen, Durchfall, Blähungen) In RCTs, the adverse event profile was comparable to placebo; 51.2% of patients reported at least one adverse event, similar to the placebo group [s5]. GI symptoms were the most common events, often difficult to distinguish from underlying disease symptoms [s4, s5]. | gelegentlich | leicht |
| Kopfschmerzen Reported in a subset of patients in studies, but without significant increase compared to placebo [s4]. | gelegentlich | leicht |
| Exazerbation entzündlicher Beschwerden (z. B. Arthritis) A community report describes an immediate arthritis exacerbation following intake; possible immunomodulatory effect in pre-existing autoimmune disease [c1]. | selten | moderat |
| Infektionen der oberen Atemwege Occasionally reported in clinical studies; no significant difference from placebo [s4]. | selten | leicht |
Contraindications
Standard contraindication; no specific allergy data from studies available [s4].
No safety data available for pregnancy or lactation; experimental status warrants caution [s4, s8].
A community case report describes an arthritis exacerbation; the immunomodulatory mechanism may influence existing inflammatory processes [c1].
Safety and dosing data for pediatric use outside of studies are lacking; a first pediatric pilot study (PIMS) is available but insufficient for general recommendations [s9].
Interactions
Synergistic
In all clinical trials, larazotide acetate was used as an adjunct to GFD. The combination showed better symptom control than GFD alone [s4, s5].
Probiotics promote upregulation and relocalization of tight junction proteins in the intestinal epithelium. Combined with larazotide, which blocks the zonulin signaling pathway, both mechanisms may complement each other and strengthen the intestinal barrier in a complementary manner.
BPC-157 promotes intestinal mucosal regeneration via collagen synthesis and anti-inflammatory effects, while larazotide specifically preserves tight junction integrity. The combination of both peptides is described as a mechanistically rational approach to repairing increased intestinal permeability.
KPV is an anti-inflammatory tripeptide that attenuates intestinal inflammatory processes. Combined with larazotide for TJ stabilization, this combination is used in peptide practice as a synergistic "leaky gut protocol."
L-glutamine is the primary fuel for enterocytes and promotes tight junction formation and maintenance of the intestinal barrier. In combination with larazotide, both substances may reduce intestinal permeability via different mechanisms.
Berberine improves intestinal barrier function partly through modulation of TJ proteins (occludin) and exerts concurrent anti-inflammatory effects in the gut. A combination with larazotide could favorably influence the zonulin pathway and TJ expression in parallel.
Curcumin exerts anti-inflammatory effects in the gut and can support intestinal barrier function. Together with larazotide as a TJ regulator, it may improve control of intestinal inflammation and permeability.
Apigenin possesses anti-inflammatory properties in the gut and can support intestinal barrier function. Combined with larazotide, which blocks the zonulin pathway, both substances may promote gut health in a complementary manner.
Butyrate is an important nutrient for colonocytes and promotes the expression of tight junction proteins and mucosal integrity. Together with larazotide, it may strengthen the intestinal barrier both structurally and regulatorily.
Caution
Theoretical interaction via additive immunomodulation; no clinical data available [s1].
Possible influence on the local intestinal milieu; no data available. Caution with concurrent use of substances sharing a similar intestinal site of action [s1].
Betaine HCl increases gastric acid and can significantly lower gastric pH. As larazotide is an acid-sensitive oral peptide, concurrent administration with betaine HCl could theoretically reduce the stability and bioavailability of larazotide.
Proteolytic digestive enzymes (e.g., proteases, bromelain, papain) may prematurely degrade orally administered larazotide peptide, thereby reducing its efficacy. A time interval between administration of both substances is recommended.
Studies
Tier A — High Evidence
Effect Size: Primary endpoint (mean CeD-GSRS score during treatment): 0.5 mg arm met the primary endpoint vs. placebo (p significant; exact values: −0.34 points mean difference [95% CI not extractable from open-access sources – full-text access required]). Higher doses (1 mg, 2 mg) showed no significant effect.
Tier B — Moderate Evidence
Community Evidence
Top reported benefits
- Theoretical interest as an intestinal permeability regulator in biohacking circles
- Single case report of use in autoimmune disease
Top reported issues
- Arthritis exacerbation following administration (single case, r/Peptides)
- Scarcely available anecdotal reports
- Sourcing only through grey-market suppliers with unknown quality
The community data base is extremely limited (fewer than 10 relevant posts identified). Larazotide acetate is only marginally discussed in r/Peptides and German biohacker forums. The only concrete user experience describes a negative reaction [c1]. Grey market sourcing carries considerable quality and safety risks [c2]. A reliable community assessment is currently not possible.
Scientific Sources
- Larazotide acetate: a pharmacological peptide approach to tight junction regulation
Kaymak T, Farré R, Tack J, et al. (2021). American Journal of Physiology-Gastrointestinal and Liver PhysiologyBDOI - Buy Larazotide 5mg – Research Grade (vendor listing)
PeptidesSource (2024). PeptidesSource commercial listingDLink - Larazotide acetate for treatment of celiac disease: A systematic review and meta-analysis of randomized controlled trials
Hoilat GJ, Altowairqi AK, Ayas MF et al. (2022). Clinics and Research in Hepatology and GastroenterologyBPMID:34339872DOI - Viral spike antigen clearance and augmented recovery in children with post-COVID multisystem inflammatory syndrome treated with larazotide
Yonker LM et al. (2025). Science Translational MedicineBPMID:40737433DOI - The safety, tolerance, pharmacokinetic and pharmacodynamic effects of single doses of AT-1001 in coeliac disease subjects: a proof of concept study
Paterson BM, Lammers KM, Arrieta MC, Fasano A, Meddings JB (2007). Alimentary Pharmacology & TherapeuticsBDOI - Larazotide (Wikipedia overview and ScienceDirect topics)
Wikipedia contributors (2024). Wikipedia / ScienceDirectCLink - Larazotide (AT-1001): Research Evidence & Safety Profile
PeptideInsight editorial team (2024). PeptideInsightCLink - Larazotide Acetate for Persistent Symptoms of Celiac Disease Despite a Gluten-Free Diet: A Randomized Controlled Trial
Leffler DA, Kelly CP, Green PH, et al. (2015). GastroenterologyAPMID:25683116DOI - A Randomized, Double-Blind Study of Larazotide Acetate to Prevent the Activation of Celiac Disease During Gluten Challenge
Kelly CP, Green PH, Murray JA, et al. (2013). American Journal of GastroenterologyAPMID:22825365DOI - Larazotide acetate for treatment of celiac disease: A systematic review and meta-analysis of randomized controlled trials
Elli L, Branchi F, Sidhu R, et al. (2021). Clinical and Translational GastroenterologyAPMID:34339872DOI - Larazotide Acetate for Treatment of Celiac Disease: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
Mukherjee R, Kelly CP, Marchese A, et al. (2020). medRxiv (preprint)BDOI - Phase 3 study of larazotide acetate to treat celiac disease discontinued
Beyond Celiac editorial team (2020). BeyondCeliac.orgBLink - Klinische Studie findet sichere und wirksame Behandlung für Kinder mit PIMS (Larazotid)
Biermann Medizin Redaktion (2023). Biermann MedizinCLink
Community Sources
Storage
Unopened
According to manufacturer specifications from research chemical suppliers, store at -20 °C or 2–8 °C; protect from light.
Opened
After opening, store at 2–8 °C and use promptly; precise stability data for reconstituted solutions have not been published.
Notes
As no approved finished pharmaceutical dosage form exists, storage instructions derive exclusively from research chemical suppliers without regulatory validation [s10].