What Is GLP-1? Definition for Peptide Research

GLP-1

Also known as: Glucagon-like peptide-1, GLP1, Incretin

GLP-1 is glucagon-like peptide-1, a naturally occurring hormone produced in the intestines that regulates blood sugar levels by stimulating insulin release, slowing gastric emptying, and reducing appetite. GLP-1 receptor agonists are a class of medications that mimic this hormone's effects.

Last updated: January 20, 2026

How GLP-1 Works

GLP-1 is released from L-cells in the intestine in response to food intake. Once released, it performs several important functions:

Stimulates insulin secretion - GLP-1 acts on pancreatic beta cells to increase insulin release in a glucose-dependent manner
Inhibits glucagon release - Reduces the hormone that raises blood sugar
Slows gastric emptying - Food moves more slowly through the stomach, promoting satiety
Acts on the brain - Reduces appetite through central nervous system effects

GLP-1 in Peptide Research

GLP-1 receptor agonists are among the most extensively researched peptide-based medications. They work by mimicking the effects of natural GLP-1 but with modifications that extend their duration of action.

Key GLP-1 Receptor Agonists

Semaglutide (Ozempic, Wegovy) - Weekly injection with high receptor affinity
Tirzepatide (Mounjaro, Zepbound) - Dual GIP/GLP-1 agonist
Liraglutide (Victoza, Saxenda) - Daily injection

Why GLP-1 Matters

Understanding GLP-1 is essential for interpreting research on metabolic peptides. The GLP-1 pathway has become one of the most important targets in obesity and diabetes research, with several FDA-approved medications now available.

Frequently Asked Questions

What does GLP-1 stand for?

GLP-1 stands for glucagon-like peptide-1. It’s called “glucagon-like” because its precursor molecule (proglucagon) also produces glucagon, though GLP-1 has opposite effects on blood sugar.

Is GLP-1 the same as semaglutide?

No. GLP-1 is a natural hormone your body produces. Semaglutide is a synthetic GLP-1 receptor agonist - a medication designed to mimic GLP-1’s effects but with modifications that make it last longer in the body.

How long does natural GLP-1 last?

Natural GLP-1 has a very short half-life of only 1-2 minutes due to rapid breakdown by the enzyme DPP-4. This is why GLP-1 receptor agonist medications are modified to resist this breakdown.