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Signaling peptide (guanylin family)

Guanylin

Guanylin is a 15-amino-acid peptide secreted by goblet cells of the colon and encoded by GUCA2A.

By The Peptides Codex Editorial TeamIndividual review date not recorded

Page data last changed: . Chemistry registry snapshot: . Registry refreshes and identity assessments are separate from scientific content review.

Length
15 aa
Class
Signaling peptide (guanylin family)
Function
Guanylate cyclase-C (GC-C) agonist; intestinal fluid and electrolyte transport
Context
Gastrointestinal secretion and epithelial physiology research

A 15-residue intestinal peptide that raises cGMP to drive salt and water secretion.

Also known as: GN · GUCA2A

Part of the Foundational & therapeutic peptides cluster

Overview

Guanylin is a 15-amino-acid peptide secreted by goblet cells of the colon and encoded by GUCA2A. As an endogenous agonist of the guanylate cyclase-C (GC-C) receptor, it raises intracellular cGMP to regulate intestinal chloride, bicarbonate and water transport. This page is educational and not medical advice.

Source & context

Biological / chemical source: Secreted by colonic goblet cells (GUCA2A gene)

Primary research or clinical context: Gastrointestinal secretion and epithelial physiology research

Receptor and mechanism

Guanylin activates the guanylate cyclase-C receptor on intestinal epithelium, elevating cGMP and stimulating the CFTR channel to secrete chloride and bicarbonate. It shares this pathway with uroguanylin and with bacterial heat-stable enterotoxins that mimic these peptides.

Physiological role

By regulating fluid and electrolyte movement, guanylin helps maintain intestinal and renal salt-water balance. The GC-C pathway it defines is the target of drugs such as linaclotide, underscoring the relevance of this peptide family in gut physiology.

Structure & chemistry

Molecular identity & reference confidence

Source-supported reference

Reference values are taken from the cited molecular record or curated profile. A database match is not independent laboratory verification; modifications, counter-ions, and formulations can change the measured mass.

Molecular form
Guanylin (source record; form not independently established)
Species
Not established by this molecular identity audit
Termini (N / C)
Not specified / Not specified

Average reference mass

Reference policy updated: 2026-10-05

Molecular formula
C60H94N16O22S4
Average reference mass
≈ 1,519.8
Identifiers
  • PubChem CID: 5489468
  • IUPHAR ligand: 4945
  • CAS RN: 140653-38-9

Chemistry values: PubChem, IUPHAR/BPS Guide to Pharmacology · fetched 2026-10-01.

Concentration math

Guanylin — reconstitution calculator

Enter how much peptide is in the vial and how much diluent (e.g. bacteriostatic water) is added. The tool returns the resulting solution concentration — and, for any amount you type, the volume it corresponds to. This is educational arithmetic, not a dosing recommendation.

Reference form: Guanylin (source record; form not independently established)Average reference mass: 1,519.8 Da

Syringe graduation
Solution concentration
5 mg/mL5,000 mcg/mL
mcg

Enter an amount to see the volume it corresponds to.

Educational concentration mathematics only. This tool does not recommend a dose, amount, or protocol, and nothing here is medical advice. Many peptides are not authorized by Health Canada for human use — see our reconstitution and bacteriostatic-water guides for context.

Open the Guanylin calculator on its own page →

FAQ about Guanylin

What is Guanylin?+

Guanylin is a 15-amino-acid peptide secreted by goblet cells of the colon and encoded by GUCA2A. As an endogenous agonist of the guanylate cyclase-C (GC-C) receptor, it raises intracellular cGMP to regulate intestinal chloride, bicarbonate and water transport. This page is educational and not medical advice.

What Canadian product status is recorded for Guanylin?+

Canadian product status for Guanylin has not been verified in this profile. No verified record here does not mean no authorization exists. Status depends on the product, formulation and use; consult Health Canada's product records.

What is the typical length of Guanylin?+

Guanylin is commonly described as approximately 15 amino acids (Signaling peptide (guanylin family)).

Related peptides

Uroguanylin
Signaling peptide (guanylin family)
Uroguanylin is a 16-amino-acid peptide secreted by enterochromaffin cells of the duodenum and encoded by GUCA2B. As an endogenous guanylate cyclase-C agonist, it regulates intestinal and renal electrolyte and water transport and has been implicated in appetite and post-meal fullness. This page is educational and not medical advice.
Phoenixin
Neuropeptide
Phoenixin (PNX) is a highly conserved neuropeptide first described in 2013 and processed from the SMIM20 prohormone into 14- and 20-residue forms. Signaling through the GPR173 receptor, it is studied for roles in reproduction, appetite, anxiety and energy metabolism. This page is educational and not medical advice.
Catestatin
Signaling peptide (chromogranin-derived)
Catestatin is a 21-amino-acid peptide cleaved from chromogranin A and released from neuroendocrine secretory granules. As a non-competitive nicotinic-cholinergic antagonist, it inhibits catecholamine (adrenaline/noradrenaline) release and is studied in blood-pressure regulation, metabolism and immunity. This page is educational and not medical advice.
BPC-157
Research pentadecapeptide (gastric-juice-derived sequence)
BPC-157 (Body Protection Compound-157) is a synthetic 15-residue peptide, GEPPPGKPADDAGLV, derived from a sequence found in human gastric juice. Hundreds of rodent studies, most from a single Zagreb group, report accelerated healing of tendon, muscle, ligament, gut and skin injuries via VEGFR2, nitric-oxide and ERK1/2 pathways. Human evidence is limited to a small safety study and a retrospective chart review; the first phase 2 efficacy trial began recruiting in 2026. It is not approved anywhere and the FDA barred it from compounding in 2023.

References & further reading

  1. 1.Cohen (1995). Wherefore art thou guanylin?. Gastroenterology
  2. 2.Ikpa et al. (2016). Guanylin and uroguanylin are produced by mouse intestinal epithelial cells of columnar and secretory lineage. Histochem Cell Biol
  3. 3.Whitaker et al. (1997). The uroguanylin gene (Guca1b) is linked to guanylin (Guca2) on mouse chromosome 4. Genomics
  4. 4.Brenna Ø et al. (2016). Cellular localization of guanylin and uroguanylin mRNAs in human and rat duodenal and colonic mucosa. Cell Tissue Res
  5. 5.Takei et al. (2007). The intestinal guanylin system and seawater adaptation in eels. Gen Comp Endocrinol
  6. 6.Forte et al. (2000). Guanylin peptides: renal actions mediated by cyclic GMP. Am J Physiol Renal Physiol
  7. 7.Otero et al. (2023). Effect of guanylin peptides on pancreas steatosis and function in experimental diet-induced obesity and after bariatric surgery. Front Endocrinol (Lausanne)
  8. 8.Rodríguez et al. (2016). Guanylin and uroguanylin stimulate lipolysis in human visceral adipocytes. Int J Obes (Lond)
  9. 9.PMC — Guanylin, Uroguanylin and Guanylate Cyclase-C in the GI tract
  10. 10.Wikipedia — Guanylin
Disclaimer: Educational content only. Not medical advice. Not instructions for human use. Research peptides and unapproved products may be restricted or illegal to market for human consumption in your jurisdiction. Consult qualified professionals and applicable law.
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