PeptideHormone

Ghrelin

Stomach-derived hunger signal that also amplifies GH pulses.

EndogenousEstablished

Identity

Class
Acylated peptide hormone (28 aa)
Source
Stomach (X/A-like cells)
Receptor
Growth hormone secretagogue receptor (GHS-R1a)

Key properties

Molecular weight
~3,370.9 Da
Half-life (native)
~30 min (acyl-ghrelin)
Model dosing

Approximate values for the native hormone. Engineered analogs are often deliberately larger and far longer-acting.

Mechanism

Ghrelin acts at GHS-R1a — a different receptor from GHRH — to amplify GH secretion, and centrally to drive appetite. Its activity depends on a unique acyl modification, making the acylating enzyme GOAT part of its biology.

Reference notes

  • Ghrelin is the endogenous ligand for the receptor that synthetic GH secretagogues (GHRPs) target.
  • It is one of the few clearly orexigenic (hunger-promoting) circulating hormones.
  • Its acyl modification is required for GHS-R1a activity — an unusual structural requirement.

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. 1.The Homeostatic Force of Ghrelin · Cell metabolism, 2018 · PMID 29576534
  2. 2.The role of leptin and ghrelin in the regulation of food intake and body weight in humans: a review · Obesity reviews : an official journal of the International Association for the Study of Obesity, 2007 · PMID 17212793