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All peptides
GastrointestinalResearch Phase

Guanylin

Endogenous peptide
Written by Peptide Association Editorial TeamMedically reviewed by Ian Justl Ellis, MD, CPTLast reviewed Editorial policy

Overview

Guanylin is a 15-amino acid endogenous peptide hormone that activates guanylate cyclase-C (GC-C) receptors on intestinal epithelial cells. Upon binding, it stimulates intracellular cyclic GMP production, which regulates chloride and bicarbonate secretion into the intestinal lumen and promotes fluid secretion.

Mechanism of Action

This mechanism enhances intestinal motility and fluid balance. Guanylin functions as a paracrine regulator of intestinal homeostasis and salt-water equilibrium.

Research Summary & Key Findings

Guanylin itself has been characterized primarily in preclinical studies elucidating its role in intestinal fluid regulation and epithelial cell function. Synthetic analogs of guanylin, such as linaclotide and plecanatide, have been developed and approved for clinical use in chronic constipation and irritable bowel syndrome with constipation. Native guanylin remains a research tool rather than a therapeutic agent.

Clinical Status

Research Phase

Guanylin 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

Endogenous peptide

References

Primary literature

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.

Related Peptides in Gastrointestinal

No lawful pathway today

Guanylin 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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One email, only if this compound's regulatory standing actually moves. Not a newsletter, not a sales sequence.

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Disclaimer: 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.