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Alpha-Defensin 5
Overview
Alpha-defensin 5 (HD5) is a 32-amino acid cationic peptide predominantly expressed by Paneth cells in the small intestinal crypts. It contains three disulfide bonds that stabilize its beta-sheet structure and enable membrane disruption of bacteria, fungi, and some viruses.
Mechanism of Action
HD5 plays a critical role in maintaining intestinal homeostasis by regulating gut microbiota composition and protecting the epithelial barrier. Altered HD5 expression has been implicated in inflammatory bowel disease, necrotizing enterocolitis, and susceptibility to enteric infections.
Research Summary & Key Findings
Preclinical studies have demonstrated that HD5 deficiency in mouse models increases susceptibility to intestinal pathogens and dysbiosis. Observational human studies have correlated reduced HD5 expression with Crohn disease severity and neonatal gut inflammation. Therapeutic strategies to augment HD5 expression or deliver recombinant peptide remain in early research stages with no clinical trials reported.
Clinical Status
Alpha-Defensin 5 is in the research phase with limited clinical data in humans. Current evidence is primarily derived from preclinical (animal or in vitro) studies.
Administration Routes
References
Primary literature
- PubMed: "Alpha-Defensin 5"
Peer-reviewed literature indexed by the National Library of Medicine.
- ClinicalTrials.gov: "Alpha-Defensin 5"
Registered interventional and observational studies, including status and phase.
- PubChem: "Alpha-Defensin 5"
Chemical structure, molecular properties, and bioactivity data.
Study-level citations for this compound are being verified against the primary sources before publication. The database queries above return the current indexed literature in the meantime.
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View detailsNo lawful pathway today
Alpha-Defensin 5 is not FDA-approved and does not currently have a lawful prescription or compounding pathway in the United States, so there is nothing for us to sell you here and no consultation to book. That can change: eight peptides moved back to a lawful pathway in February 2026.
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List Your PracticeDisclaimer: This information is provided for educational and research purposes only. It is not intended as medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before starting any peptide therapy. The Peptide Association does not endorse or recommend any specific treatment protocol. See our editorial policy for how this content is produced and reviewed.