Does Larazotide acetate (AT-1001) work?

Read Off Label rates the evidence for Larazotide acetate (AT-1001) as Weak and the benefit magnitude as weak, producing an overall grade of D+ (3.4/10). Failed Ph3 primary endpoint in celiac disease 2022 despite promising Ph2b.

Is Larazotide acetate (AT-1001) safe?

Larazotide acetate (AT-1001) has a unclear risk profile in published human data. Legal status: Not FDA-approved; 9 Meters discontinued development; gray-market research peptide. This is not medical advice — see the disclaimer.

Rankings / Immune & Inflammation

Larazotide acetate (AT-1001)

Immune & Inflammation · Tight junction regulator

Tier D+

Reviewed by Read Off Label · Last reviewed Jun 8, 2026 · How we grade

peptideresearch-only

3.4 / 10

Tier D+

Ev 3 Bn 3 Sf 4

Bottom line

Read Off Label grades Larazotide acetate (AT-1001) as D+ (3.4/10) based on weak evidence, weak benefit magnitude, and a unclear-risk safety profile.

Failed Ph3 primary endpoint in celiac disease 2022 despite promising Ph2b.

Typical use: 0. — Not FDA-approved; 9 Meters discontinued development; gray-market research peptide.

What this is

Failed Ph3 primary endpoint in celiac disease 2022 despite promising Ph2b. Some use in 'leaky gut' biohacker protocols despite the failed trial. Mechanism is legitimate but real-world benefit unproven.

Mechanism

Octapeptide zonulin antagonist; tightens intestinal tight junctions; reduces intestinal permeability; developed for celiac disease adjunct to GFD

Dose & route

0.5 mg PO 3x/day in trials

Citations

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Common questions

Does Larazotide acetate (AT-1001) work?: Read Off Label rates the evidence for Larazotide acetate (AT-1001) as Weak and the benefit magnitude as weak, producing an overall grade of D+ (3.4/10). Failed Ph3 primary endpoint in celiac disease 2022 despite promising Ph2b.
Is Larazotide acetate (AT-1001) safe?: Larazotide acetate (AT-1001) has a unclear risk profile in published human data. Legal status: Not FDA-approved; 9 Meters discontinued development; gray-market research peptide. This is not medical advice — see the disclaimer.
What is the typical dose for Larazotide acetate (AT-1001)?: 0.5 mg PO 3x/day in trials
How does Larazotide acetate (AT-1001) work?: Octapeptide zonulin antagonist; tightens intestinal tight junctions; reduces intestinal permeability; developed for celiac disease adjunct to GFD

This is an independent synthesis of published research by a non-clinician. Scores are opinions supported by citations, not prescriptions. See the full disclaimer and methodology for how this score was produced and what it does and doesn't mean.