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Gut hormone

Gastrin

Gastrin is a peptide hormone released by G-cells of the gastric antrum that stimulates acid secretion from the stomach's parietal cells. Circulating in several lengths such as gastrin-17 and gastrin-34, it is a foundational hormone in digestive physiology and in the study of acid-related disorders.

By The Peptides Codex Editorial TeamReviewed July 10, 2026
Length
n/a
Class
Gut hormone
Function
Stimulates gastric acid secretion and gastric mucosal growth
Context
Endogenous hormone; central to acid-physiology and Zollinger–Ellison research

The master driver of stomach-acid secretion — and a shared receptor with CCK.

Also known as: gastrin-17 · gastrin-34

Part of the Metabolic & GLP-1 peptides cluster

Overview

Gastrin is a peptide hormone released by G-cells of the gastric antrum that stimulates acid secretion from the stomach's parietal cells. Circulating in several lengths such as gastrin-17 and gastrin-34, it is a foundational hormone in digestive physiology and in the study of acid-related disorders.

Source & context

Biological / chemical source: G-cells of the stomach antrum and duodenum

Primary research or clinical context: Endogenous hormone; central to acid-physiology and Zollinger–Ellison research

Structure and the CCK connection

Gastrin and cholecystokinin share the same C-terminal amidated pentapeptide, so they can act on overlapping receptors — gastrin works mainly through the CCK-B (CCK-2) receptor. The mature hormone also carries a sulfated tyrosine and circulates as multiple processed forms, illustrating peptide-family relatedness through shared motifs.

Physiology and clinical relevance

By driving parietal-cell acid output and mucosal growth, gastrin sits at the center of digestive physiology. Excess gastrin, as in gastrinoma (Zollinger–Ellison syndrome), is a classic teaching example. Coverage here is educational and describes hormone biology rather than diagnosis or treatment.

FAQ about Gastrin

What is Gastrin?+

Gastrin is a peptide hormone released by G-cells of the gastric antrum that stimulates acid secretion from the stomach's parietal cells. Circulating in several lengths such as gastrin-17 and gastrin-34, it is a foundational hormone in digestive physiology and in the study of acid-related disorders.

Is Gastrin an approved medicine?+

Gastrin is discussed here as a research / educational topic. Endogenous hormone; central to acid-physiology and Zollinger–Ellison research. This is not medical advice.

What is the typical length of Gastrin?+

Gastrin is not a classic amino-acid chain peptide in the same sense; see the profile for classification details.

Related peptides

Oxyntomodulin
Gut hormone
Oxyntomodulin is a 37-amino-acid gut hormone released from intestinal L-cells after eating. Because it activates both the GLP-1 and glucagon receptors on its own, it is frequently cited as the natural inspiration for engineered dual-agonist metabolic peptides.
Secretin
Hormone
Secretin is a 27-amino-acid hormone released from duodenal S-cells in response to stomach acid entering the small intestine. Discovered by Bayliss and Starling in 1902, it was the first substance ever called a hormone and remains a landmark in the history of endocrinology.
Motilin
Gut hormone
Motilin is a 22-amino-acid gut hormone secreted by endocrine cells of the small intestine. It coordinates the migrating motor complex, the wave of contractions that clears the digestive tract between meals, earning it the nickname the housekeeper of the gut.
Peptide YY
Gut hormone
Peptide YY (PYY) is a 36-amino-acid gut hormone released from intestinal L-cells after eating, where it contributes to satiety and slows gastric emptying. Named for its tyrosine residues at each end, it is a heavily studied signal in appetite and energy-balance research.

References & further reading

  1. 1.Wikipedia — Gastrin
  2. 2.PubChem — compound summary for Gastrin (CID 44288444)
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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Cite this: Peptides Codex — Gastrin educational profile.
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