CGRP vs Larazotide

Binds CLR/RAMP1 receptor complex. Causes vasodilation via cAMP/PKA/nitric oxide pathway. Modulates nociceptive signaling in the trigeminal system. Promotes bone healing and has anti-inflammatory effects in peripheral tissues.

CGRP (calcitonin gene-related peptide) is a 37-amino-acid endogenous neuropeptide produced by alternative splicing of the calcitonin gene, expressed predominantly in sensory neurons of the trigeminal system and peripheral vasculature, where it functions as a potent vasodilator and pain neuromodulator central to migraine pathophysiology. CGRP activates its receptor complex (CLR/RAMP1) to mediate vasodilation and nociceptive signal amplification; during migraine attacks, trigeminal activation releases CGRP at elevated plasma concentrations, and blockade of this pathway has been established as the primary validated pharmacological target for modern preventive migraine therapy. Phase 3 randomized controlled trials published in the New England Journal of Medicine and the Lancet — including the STRIVE trial (Goadsby et al. 2017) and a Phase 3b study in treatment-refractory patients — demonstrated that anti-CGRP monoclonal antibodies significantly reduced monthly migraine days versus placebo, validating the pathway and supporting FDA approval of erenumab, fremanezumab, and galcanezumab. CGRP itself is an endogenous neuropeptide and is not a therapeutic agent that is compounded or administered by providers; the FDA-approved interventions are monoclonal antibody and small-molecule receptor antagonists available by prescription, and exogenous CGRP peptide is exclusively a research tool compound used in vasodilatory and pain signaling pharmacology studies.

Synthetic octapeptide that prevents zonulin-mediated tight junction opening; maintains intestinal epithelial barrier integrity

Larazotide acetate (AT-1001) is a synthetic octapeptide zonulin antagonist that reduces intestinal permeability by blocking zonulin-mediated disassembly of intestinal epithelial tight junctions, studied as an adjunctive treatment to reduce symptom burden in celiac disease patients during inadvertent or deliberate gluten exposure. By inhibiting zonulin receptor signaling, larazotide prevents the disruption of tight junction proteins — including occludin and claudins — that would otherwise permit immunogenic gluten peptides to traverse the epithelial barrier and trigger the CD4+ T-cell-mediated mucosal injury characteristic of active celiac disease. A Phase 2 randomized, double-blind trial published in The American Journal of Gastroenterology demonstrated that larazotide acetate reduced activation of celiac disease during gluten challenge; however, the Phase 3 trial published in Gastroenterology, designed to evaluate larazotide for persistent symptoms in celiac disease patients already following a gluten-free diet, did not meet its primary endpoint. Larazotide has not received FDA approval; no NDA has been filed following the Phase 3 outcome, and it remains an investigational compound with no approved indication.