Larazotidesafety profile & UK regulatory status
Research reference
Reviewed by the BestHealingPeptides Editorial Team ·
This page summarises the published safety profile, contraindications, formulation interactions, and UK regulatory status for Larazotide as reported in the pre-clinical research literature. It is a research-orientation reference and not a clinical safety assessment. Larazotide is not licensed as a medicine in the United Kingdom and may not be supplied or administered to humans outside an authorised clinical-trial framework.
Safety profile
Larazotide acetate has demonstrated a consistently favourable tolerability profile across its clinical-trial programme, which represents the most extensive human safety dataset available for any research peptide targeting the intestinal barrier. In the Phase IIb trial (Leffler et al., Gastroenterology, 2015), the most common adverse events were mild-to-moderate gastrointestinal symptoms, including headache, nausea, flatulence, and abdominal pain. The rate of serious adverse events did not significantly differ between active treatment arms and placebo. No clinically significant changes in laboratory parameters (haematology, biochemistry, urinalysis) were observed. The overall adverse-event profile was comparable between larazotide and placebo, which reflects the fact that the patient population (coeliac disease) has a background of gastrointestinal symptoms that confounds attribution. The principal pharmacological feature underpinning the safety profile is minimal systemic absorption. Because larazotide acts at the luminal surface and does not appreciably enter the systemic circulation, there is no significant exposure of non-gastrointestinal tissues to the drug. This is a fundamental difference from systemically absorbed peptide drugs, which must be considered in the context of distribution, metabolism, and potential off-target effects in every organ. There are no established serious adverse effects attributable to larazotide in the published clinical record. As a foreign octapeptide, immunogenicity is theoretically possible with repeated dosing, but was not a clinical issue in the trials conducted. Long-term safety data beyond 12-week treatment periods are limited in the published record.
Reported contraindications & cautions
- No established clinical contraindications (not a licensed medicine)
- No specific contraindications identified in clinical trials to date
- Safety in pregnancy and lactation is unstudied
- Severe renal or hepatic impairment: not specifically studied, though minimal systemic absorption makes systemic accumulation unlikely
Known formulation interactions
- No clinically significant drug interactions identified in Phase II trials; minimal systemic absorption limits systemic pharmacokinetic interactions
- Theoretically, other agents affecting tight-junction integrity (e.g., zonulin-modulating therapies, intestinal barrier supplements) could have additive or antagonistic effects — not formally studied
- No known interactions with standard coeliac disease management (gluten-free diet, corticosteroids for refractory disease)
UK regulatory status
Larazotide acetate (AT-1001 / INN-202) is not authorised as a medicinal product by the UK Medicines and Healthcare products Regulatory Agency (MHRA) and holds no marketing authorisation in any jurisdiction as of the current date. It is not a controlled substance under the Misuse of Drugs Act 1971. Larazotide is not listed on the World Anti-Doping Agency (WADA) Prohibited List, nor would its pharmacological mechanism (tight-junction modulation, no systemic anabolic or ergogenic effect) obviously fall within any current WADA category. Athletes can obtain clarity from their sport's anti-doping body, but larazotide does not appear to represent a doping concern. No UK MHRA enforcement actions against larazotide supply are known to this publication. Research-grade larazotide acetate for in-vitro and ex-vivo laboratory use is available from research-chemical suppliers; possession for laboratory research is unrestricted. Supply for human administration outside an authorised clinical-trial framework would engage the Human Medicines Regulations 2012. UK patients with coeliac disease and persistent symptoms should discuss management with their gastroenterologist; larazotide is not available as a prescription medicine in the UK.
What 'research-use-only' means in the UK
The UK regulatory position on research peptides sits across four distinct frameworks: MHRA medicines licensing, the Human Medicines Regulations 2012, the Misuse of Drugs Act 1971, and the WADA Prohibited List. Larazotide is not an MHRA-licensed medicine; possession for bona fide in-vitro or ex-vivo laboratory research is generally lawful, while supply or administration to humans engages the Human Medicines Regulations and is generally an offence. For animal-research use, additional permissions are required under the Animals (Scientific Procedures) Act 1986 (ASPA).
For the comprehensive UK regulatory reference covering all four frameworks, see the UK research peptide regulation 2026 reference.
Practical safety considerations for research
Sterility and endotoxin content of research-grade preparations remain the dominant practical safety variables for any injectable in-vivo work, regardless of the intrinsic safety profile of the active peptide. Batch-to-batch verification of HPLC purity and identity (by mass spectrometry where possible) and endotoxin testing by limulus amebocyte lysate (LAL) assay or recombinant Factor C (rFC) assay are standard due-diligence expectations. For research with vertebrate animals in the UK, ASPA project and personal licences are mandatory and the work must pass a local Animal Welfare and Ethical Review Body assessment.
For full Larazotide research context including mechanism, study citations, and references, see the main Larazotide research profile. For dosing and pharmacokinetic context, see the dosing reference and half-life reference pages.