Gastrointestinal · Research Phase
Guanylin
No lawful US pathway
01 · Overview
Guanylin is a 15-amino acid peptide hormone that activates guanylate cyclase-C (GC-C) receptors on intestinal epithelial cells. Binding raises intracellular cyclic GMP, which drives intestinal secretion of chloride and bicarbonate (PMID 15518884).
Guanylin is mainly restricted to the intestine and is secreted into the lumen and blood, including in response to salt intake (PMID 11324723). It acts as a local regulator of intestinal fluid and electrolyte balance and of epithelial cell turnover (PMID 15518884).
02 · Research summary & key findings
Guanylin has been characterized mainly in laboratory and animal studies of intestinal and renal salt and water handling, where guanylin peptides inhibit sodium absorption in the gut and promote sodium excretion by the kidney (PMID 24967239). Bacterial heat-stable enterotoxins mimic guanylin and uroguanylin structurally and act on GC-C to cause secretory diarrhea (PMID 11324723). The approved GC-C agonist linaclotide is a synthetic analogue of the E. coli heat-stable enterotoxin, whereas plecanatide is an analogue of uroguanylin rather than guanylin (PMID 28357122). Native guanylin itself remains a research tool rather than a therapeutic agent.
03 · Regulatory status
Guanylin is in the research phase with limited clinical data in humans. Current evidence is primarily derived from preclinical (animal or in vitro) studies.
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 we do not sell it and will not book a consultation for it. That can change: in 2026 FDA began reviewing several peptides for compounding.
See the 7 FDA-approved compounds in Gastrointestinal
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04 · Administration routes
- Endogenous peptide
References
- [1]Guanylin family: new intestinal peptides regulating electrolyte and water homeostasis J Gastroenterol, 2001. PMID 11324723
- [2]Uroguanylin and guanylin peptides: pharmacology and experimental therapeutics Pharmacol Ther, 2004. PMID 15518884
- [3]Current understanding of guanylin peptides actions ISRN Nephrol, 2013. PMID 24967239
- [4]Therapeutically targeting guanylate cyclase-C: computational modeling of plecanatide, a uroguanylin analog Pharmacol Res Perspect, 2017. PMID 28357122
Primary literature
- PubMed: "Guanylin"
Peer-reviewed literature indexed by the National Library of Medicine.
- ClinicalTrials.gov: "Guanylin"
Registered interventional and observational studies, including status and phase.
- PubChem: "Guanylin"
Chemical structure, molecular properties, and bioactivity data.
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