GLP-1 Receptor Agonist

Key facts

FDA established pharmacologic class

Glucagon-Like Peptide-1 (GLP-1) Receptor Agonist

First U.S. approval

Exenatide (Byetta), 2005

Application types

Most are peptides approved under NDAs; dulaglutide is licensed under a BLA

Dual agonist in the market

Tirzepatide acts on both GIP and GLP-1 receptors

What is a GLP-1 receptor agonist?

Glucagon-like peptide-1 (GLP-1) is an incretin hormone released by the gut after eating. Natural GLP-1 breaks down within minutes, so drugs in this class are engineered to resist breakdown and act for a day or a week.

Marketed agents include exenatide, liraglutide (Victoza, Saxenda), dulaglutide (Trulicity) and semaglutide (Ozempic, Wegovy, Rybelsus). Tirzepatide (Mounjaro, Zepbound) activates both the GIP and GLP-1 receptors and is often grouped with the class, although it is a dual agonist.

Most products are daily or weekly injections, and oral semaglutide is available as a tablet. The same molecule is often sold under different brand names and doses for diabetes and for weight management.

How the GLP-1 market is structured

The class is organized around shared molecules sold under several labels:

• Indications: approved uses across products include type 2 diabetes, chronic weight management and cardiovascular risk reduction, and specific products carry further indications such as obstructive sleep apnea or chronic kidney disease.
• Brand pairs: Ozempic and Wegovy (semaglutide), Mounjaro and Zepbound (tirzepatide), and Victoza and Saxenda (liraglutide) split diabetes and weight management labeling.
• Generics: generic exenatide and liraglutide were approved in late 2024, while semaglutide and tirzepatide remain protected by patents in the United States.
• Compounding: shortages from 2022 to 2025 allowed widespread compounding of semaglutide and tirzepatide, which the FDA restricted after declaring the shortages resolved.

Why GLP-1 receptor agonists matter

GLP-1 drugs sit at the center of current drug spending and coverage debates:

• Spending: GLP-1 drugs have become one of the largest and fastest-growing drug spending categories in Medicare Part D, Medicaid and commercial plans.
• Coverage policy: the Medicare Part D statute excludes drugs used for weight loss, so plans cover these drugs for diabetes, cardiovascular risk reduction and other accepted uses. Federal and state policy on obesity coverage changed repeatedly between 2024 and 2026, so check the rules for the current year.
• Price negotiation: semaglutide was among the drugs selected in January 2025 for the second cycle of Medicare drug price negotiation, with negotiated prices taking effect in 2027.
• Monitoring: the class appears in FDA shortage records, adverse event reports and warnings about unapproved compounded versions, so linking those sources supports supply and safety tracking.