GLP-1 Receptor Agonists: A Guide to the Drug Class

What is a GLP-1 receptor agonist?

GLP-1 (glucagon-like peptide-1) is a hormone released by the intestine. Medicines called GLP-1 receptor agonists activate its receptor. GLP-1 signaling helps regulate blood glucose after meals and affects appetite and food intake. Drug effects and approved uses depend on the particular product, rather than on the class name alone. FDA class explanation

Semaglutide is a GLP-1 receptor agonist. Tirzepatide, the ingredient in Mounjaro and Zepbound, activates both GIP and GLP-1 receptors. It is often discussed alongside GLP-1 medicines, but it is a dual agonist, not a GLP-1-only agonist. Mounjaro label · Zepbound label

Why the brand and formulation matter

These examples describe U.S. label indications as of September 2026, not interchangeable uses for every medicine in the class:

Ingredient and product	U.S. label scope
Semaglutide — Ozempic injection	Type 2 diabetes glucose control in adults; specified cardiovascular and kidney risk reduction in adults with type 2 diabetes who meet the label criteria. Ozempic label
Semaglutide — Wegovy injection	Long-term weight reduction in the populations named in its label, cardiovascular risk reduction in certain adults, and accelerated approval for noncirrhotic MASH with F2–F3 fibrosis in adults. Wegovy label
Semaglutide — Wegovy tablets	Long-term weight reduction and cardiovascular risk reduction in specified adults. The tablet label does not carry the injection’s pediatric weight or MASH indications. Wegovy label
Tirzepatide — Mounjaro injection	Type 2 diabetes glucose control in adults and children age 10 years and older. Mounjaro label
Tirzepatide — Zepbound injection	Long-term weight reduction in specified adults and treatment of moderate-to-severe obstructive sleep apnea in adults with obesity. Zepbound label

The same ingredient can therefore appear under different brands, formulations, and approved uses. A trial result or indication for one product should not be assigned to every GLP-1 medicine.

How to read a label’s safety section

The cited labels describe gastrointestinal adverse reactions and warnings that include acute pancreatitis, gallbladder events, and a boxed warning about thyroid C-cell tumors seen in rodents. The human relevance of the rodent tumor finding remains unknown. Contraindications and other warnings differ by product, so the complete current label is the relevant source for a particular medicine. Wegovy label · Zepbound label

Evidence note: The product and safety statements above come from FDA labeling, a high-confidence source for U.S. approved uses. They do not establish that all products have the same benefits or risks. This guide is educational and does not provide medical advice or treatment recommendations.

For a dated account of the newer approvals and trial evidence, see GLP-1 drugs: what changed through September 2026.

Sources & Citations

• 1

  regulatory

  FDA Requests Removal of Suicidal Behavior and Ideation Warning from GLP-1 RA Medications (January 2026)

  fda-glp1-safety-2026

• 2

  regulatory

  OZEMPIC (semaglutide) U.S. Prescribing Information (revised May 2026)

  fda-ozempic-label-2026-209637s038

• 3

  regulatory

  WEGOVY (semaglutide) injection and tablets U.S. Prescribing Information (revised June 2026)

  fda-wegovy-label-2026-218316s007

• 4

  regulatory

  MOUNJARO (tirzepatide) U.S. Prescribing Information (revised January 2026)

  fda-mounjaro-label-2026-215866s041

• 5

  regulatory

  ZEPBOUND (tirzepatide) U.S. Prescribing Information (revised August 2026)

  fda-zepbound-label-2026-217806s041