GLP-1
Definition
Glucagon-Like Peptide-1 (GLP-1) is a 30/31-amino-acid incretin hormone produced by intestinal L-cells in response to food intake. It is one of the most clinically significant peptide hormones, forming the basis of multiple approved therapies for type 2 diabetes and obesity.
Mechanism and Signalling
GLP-1 binds the GLP-1 receptor (GLP-1R), a G protein-coupled receptor expressed on pancreatic beta cells, neurons, cardiac tissue, and gastrointestinal tract. Its key effects include:
- Glucose-dependent insulin secretion — Enhances insulin release only when blood glucose is elevated
- Glucagon suppression — Reduces hepatic glucose output by inhibiting alpha cell glucagon secretion
- Gastric motility — Slows gastric emptying, contributing to satiety
- Central appetite regulation — Acts on hypothalamic and brainstem circuits to reduce food intake
Native GLP-1 has a half-life of only 1–2 minutes due to rapid degradation by DPP-4. This short half-life drove the development of DPP-4-resistant analogues.
Relevance to Peptide Research
GLP-1 receptor agonists represent the largest class of peptide-based therapeutics in current clinical use. Semaglutide, liraglutide, dulaglutide, and exenatide are all GLP-1R agonists with varying half-lives and delivery routes. The success of GLP-1 agonists has catalysed research into combination approaches — tirzepatide (GIP/GLP-1), retatrutide (GIP/GLP-1/glucagon), and survodutide (GLP-1/glucagon) — that build on GLP-1 pharmacology.
Related Peptides
Peptide profiles that reference “GLP-1” in their research content.