Stimulates pancreatic bicarbonate to neutralize gastric acid. Structurally it is Secretin-family peptide (27 aa).

How strong is the evidence for Secretin?

PeptideHormone grades Secretin at the "Established" evidence tier — its mechanism and core effects are settled across the peer-reviewed literature. It is catalogued as an endogenous signal the body produces itself, and the tier is an editorial judgment about the public literature that can change as the science does.

What is the half-life of Secretin?

The reported circulating half-life of Secretin is ~4 min.

Secretin

Stimulates pancreatic bicarbonate to neutralize gastric acid.

EndogenousEstablished

The first molecule ever called a hormone. Every entry in this catalog descends from what it proved in 1902.

Identity

Class: Secretin-family peptide (27 aa)
Source: Duodenal S-cells
Receptor: Secretin receptor (a class B GPCR)

Key properties

Evidence floorClinicalREF1CLIN1

Molecular weight

~3,039.5 Da

REF

Half-life (native)

~4 min

CLIN

Model dosing

Approximate values for the native hormone; engineered analogs are often deliberately larger and far longer-acting. Each figure carries its own provenance tier, and the floor is the weakest of them - the Standard.

Mechanism

When acidic chyme enters the duodenum, S-cells release secretin, which stimulates the pancreas and bile ducts to secrete bicarbonate-rich fluid, neutralizing acid to protect the mucosa and create the pH range digestive enzymes need.

Reference notes

Secretin was the first hormone ever discovered, giving the field its name.
Its trigger is duodenal acidity — a direct chemical feedback loop.
It is the prototype of the secretin/glucagon peptide superfamily.

Common questions

What is Secretin?: Stimulates pancreatic bicarbonate to neutralize gastric acid. Structurally it is Secretin-family peptide (27 aa).
How does Secretin work?: When acidic chyme enters the duodenum, S-cells release secretin, which stimulates the pancreas and bile ducts to secrete bicarbonate-rich fluid, neutralizing acid to protect the mucosa and create the pH range digestive enzymes need.
How strong is the evidence for Secretin?: PeptideHormone grades Secretin at the "Established" evidence tier — its mechanism and core effects are settled across the peer-reviewed literature. It is catalogued as an endogenous signal the body produces itself, and the tier is an editorial judgment about the public literature that can change as the science does.
What is the half-life of Secretin?: The reported circulating half-life of Secretin is ~4 min.

Selected literature

Curated peer-reviewed reviews, sourced from PubMed. Selected for relevance, not exhaustive — open any entry on PubMed for the full record and its primary citations.

1.Secretin, 100 years later · Journal of gastroenterology, 2003 · PMID 14673718
2.Secretin: a hormone for HCO(3)(-) homeostasis · Pflugers Archiv : European journal of physiology, 2024 · PMID 38221598

External references

Secretin in the public knowledge graph — the same entity resolved across the authoritative chemistry and protein databases.