What is Peptide YY (PYY)?

A post-meal satiety signal from intestinal L-cells. Structurally it is PP-fold peptide (36 aa); active PYY3-36 form.

How strong is the evidence for PYY?

PeptideHormone grades PYY 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 PYY?

The reported circulating half-life of PYY is ~minutes.

Peptide YYPYY

A post-meal satiety signal from intestinal L-cells.

EndogenousEstablished

Secreted in proportion to how much you ate, not merely that you ate — the gut reports quantity, and the brain reads it as fullness.

Identity

Class: PP-fold peptide (36 aa); active PYY3-36 form
Source: Intestinal L-cells (with GLP-1)
Receptor: Y2 receptor (for the circulating PYY3-36 form)

Key properties

Evidence floorClinicalREF1CLIN1

Molecular weight

≈ 4,309.7 Da

REF

Half-life (native)

~minutes

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

Released after meals from the same L-cells that produce GLP-1, PYY (as PYY3-36) acts at Y2 receptors to reduce appetite. It is one of several converging gut signals that report fullness to the brain.

Reference notes

PYY and GLP-1 are co-secreted, directly linking this family to the incretin axis.
The truncated PYY3-36 form is the physiologically relevant circulating species.
Satiety is multi-signal — PYY is one contributor, not the single 'fullness hormone'.

Common questions

What is Peptide YY (PYY)?: A post-meal satiety signal from intestinal L-cells. Structurally it is PP-fold peptide (36 aa); active PYY3-36 form.
How does PYY work?: Released after meals from the same L-cells that produce GLP-1, PYY (as PYY3-36) acts at Y2 receptors to reduce appetite. It is one of several converging gut signals that report fullness to the brain.
How strong is the evidence for PYY?: PeptideHormone grades PYY 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 PYY?: The reported circulating half-life of PYY is ~minutes.

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.Incretin hormones: Their role in health and disease · Diabetes, obesity & metabolism, 2018 · PMID 29364588
2.Gut hormones and appetite regulation · Current opinion in endocrinology, diabetes, and obesity, 2024 · PMID 38511400

External references

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