Larazotide
The leading peptide candidate for "leaky gut" — it works by tightening the junctions between gut cells. Currently in Phase 3 clinical trials for celiac disease, which is further along than most peptides on this list.
This peptide is not FDA-approved for any indication. Human use outside of clinical trials is not recommended.
The basics
- Generic Name
- larazotide acetate (AT-1001)
- Brand Names
- None (not an approved product)
- Regulatory Status
- Early Research
- Therapeutic Areas
- Gastrointestinal
Wellness Goals
Important: This peptide is not yet FDA-approved
Larazotide has not been approved by the FDA for any use in humans. That means it hasn't gone through the rigorous testing process that confirms a drug is safe and effective. Products sold online have not been evaluated by any regulatory body.
What it does
Larazotide (larazotide acetate (AT-1001)) is a synthetic peptide that researchers are studying, but it's not yet FDA-approved for any human use. Tight junction regulator that blocks zonulin receptors, preventing the opening of intestinal tight junctions. Reduces paracellular permeability in the gut epithelium, keeping unwanted molecules from passing through the gut lining.
The research is still early. Most studies so far are in animals or lab settings, so we don't know for sure how well this translates to real-world results in people.
How it's taken
Oral capsule
How people access it
Currently in Phase 3 clinical trials. Available through some compounding pharmacies and research vendors. Taken orally, which is unusual for peptides — it works locally in the gut without needing to enter the bloodstream.
Regulatory Status
Not FDA-approved. In Phase 3 clinical trials for celiac disease. Being studied for gut permeability ("leaky gut").
Any use in humans outside of an FDA-authorized clinical trial would require an Investigational New Drug (IND) application. Products marketed as “for research use only” are not legally intended for human administration.
What the Evidence Shows
The evidence base for Larazotide consists primarily of preclinical studies (animal models and in vitro experiments). There are no completed, large-scale, peer-reviewed clinical trials establishing safety or efficacy in humans. The gap between promising animal data and proven human benefit is substantial — many compounds that show effects in animal studies fail to demonstrate safety or efficacy in human trials.
Marketing claims made by online sellers and “peptide clinics” frequently overstate the evidence and omit critical information about risks and unknowns.
Other options to consider
Depending on what you're hoping to achieve, there may be FDA-approved treatments that have been rigorously tested and proven to work. Discuss evidence-based options with your own healthcare provider to find what fits your specific goals.
Browse our full peptide directory to see FDA-approved options that might work for you.
Common Questions
No. Larazotide is not FDA-approved for any indication. It has no approved NDA or BLA and cannot be legally marketed as a drug for human use.
There is insufficient clinical evidence to establish the safety of Larazotide in humans. Most available data comes from preclinical studies. Using unapproved substances carries risks including unknown side effects, contamination, and incorrect dosing.
Depending on the condition you are seeking to treat, FDA-approved options may be available. Discuss evidence-based treatments with your own healthcare provider to find options that have undergone rigorous safety and efficacy review.
Curious about what IS approved?
Check out FDA-approved peptides that address similar goals — with established safety profiles and real clinical evidence.
See Approved Options