GLP stands for glucagon-like peptide, a family of hormones your gut releases after eating. The most clinically important member is GLP-1 (glucagon-like peptide-1), which lowers blood sugar, slows digestion, and reduces appetite. GLP-1 is also the target of widely used medications such as semaglutide (Ozempic, Wegovy, Rybelsus) and tirzepatide (Mounjaro, Zepbound). A second hormone in the family, GLP-2, plays a role in intestinal growth and is used medically in short bowel syndrome.
Where the Name Comes From
The name “glucagon-like peptide” reflects the molecule’s origin. GLP-1 and GLP-2 are cleaved from a larger precursor protein called proglucagon, which also gives rise to the hormone glucagon. Because GLP-1 and GLP-2 share sequence features with glucagon, researchers named them glucagon-like peptides. Despite the name, GLP-1 actually opposes some of glucagon’s actions by lowering blood sugar rather than raising it.
The hormones were first identified in the 1980s, and their physiology was mapped through the 1990s and 2000s. GLP-1 receptor agonist medications have been FDA-approved for type 2 diabetes since 2005, starting with exenatide (Byetta). For a deeper look at how these hormones affect A1C levels and daily glucose, see our dedicated hub.
What GLP-1 Does in the Body
GLP-1 has four main actions. Together, these actions explain why GLP-1 receptor agonist drugs are effective for both type 2 diabetes and obesity.
- Stimulates insulin release. GLP-1 amplifies insulin secretion from pancreatic beta cells, but only when blood sugar is elevated, which reduces the risk of hypoglycemia compared to insulin itself.
- Suppresses glucagon. GLP-1 reduces glucagon secretion from pancreatic alpha cells, limiting the liver’s glucose output between meals.
- Slows gastric emptying. Food leaves the stomach more slowly, blunting post-meal glucose spikes.
- Reduces appetite. GLP-1 acts on the brain to signal fullness and reduce food intake.
GLP-1 vs. GLP-2
Though they share a name, GLP-1 and GLP-2 have different jobs and very different clinical uses.
| Feature | GLP-1 | GLP-2 |
|---|---|---|
| Source | Intestinal L-cells | Intestinal L-cells |
| Primary role | Blood sugar and appetite regulation | Intestinal growth and absorption |
| Approved drug class | GLP-1 receptor agonists | GLP-2 analog (teduglutide) |
| Key indications | Type 2 diabetes, obesity, cardiovascular risk | Short bowel syndrome |
| Administration | Weekly or daily injection, oral tablet | Daily injection |
Why GLP-1 Dominates Headlines
Since 2017, GLP-1 receptor agonists, particularly semaglutide, have reshaped diabetes and obesity treatment. Semaglutide (Ozempic) produced A1C reductions near 2 percent and weight loss of 10 to 15 percent in trials, far larger than older diabetes drugs. Wegovy, the higher-dose semaglutide for chronic weight management, showed average weight loss near 15 percent. Tirzepatide (Mounjaro and Zepbound), a dual GLP-1 and GIP agonist, produced weight loss of 18 to 22 percent in SURMOUNT trials.
These results drove surging demand, shortages, and widespread public interest. Media coverage often uses “GLP-1” as shorthand for the entire category, even when tirzepatide is technically a dual agonist. Our treatment hub outlines the main players in detail.
Natural vs. Medication GLP-1
Natural GLP-1 is released within minutes of eating and breaks down within 1 to 2 minutes in the bloodstream. That half-life is too short to sustain a meaningful therapeutic effect. Drug developers solved this by modifying the molecule to resist breakdown, giving pharmaceutical GLP-1 agonists half-lives of hours (liraglutide) to days (semaglutide, dulaglutide). Continuous receptor activation produces stronger and longer-lasting glucose and appetite effects than the natural hormone.
Do Foods Raise GLP-1 Naturally?
Yes, within limits. Protein, fiber, healthy fats, and certain fermented foods stimulate endogenous GLP-1 release. Bitter greens, legumes, eggs, yogurt, avocado, and olive oil all promote some GLP-1 secretion. However, the increases are modest and short-lived compared to pharmaceutical agonists. Claims about “natural Ozempic” foods overstate the effect; good nutrition supports metabolic health broadly but does not replicate the sustained receptor activation of prescription drugs. Our diet and nutrition hub covers pattern-level eating habits that support healthy hormones.
Where You Might See “GLP” in Daily Life
- Prescription packaging: Semaglutide and tirzepatide labels often mention the “GLP-1” mechanism.
- News coverage: “GLP-1 drugs” is now a common headline term.
- Insurance paperwork: Prior authorization forms reference GLP-1 receptor agonist class.
- Clinical guidelines: The American Diabetes Association’s Standards of Care recommend GLP-1 receptor agonists as preferred agents for many patients with type 2 diabetes and cardiovascular risk.
For deeper background on dosing, safety, and cost, see the NIDDK resources and our own drug-specific articles in the treatment section.
The Bottom Line
GLP stands for glucagon-like peptide. GLP-1 is the version most people mean when they see “GLP” in health news: a gut hormone that lowers blood sugar, slows digestion, and reduces appetite. The enormous impact of GLP-1 receptor agonist medications on diabetes and obesity care has made the abbreviation part of everyday vocabulary. Understanding what it stands for is a useful first step toward understanding the drugs and conditions it underpins.
Medical disclaimer: This article is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your physician or qualified healthcare provider with any questions about a medical condition or treatment.
