GLP-1 Receptor Agonist
Quick Definition
A GLP-1 receptor agonist is a medication that activates the glucagon-like peptide-1 receptor, mimicking the body's GLP-1 hormone. The class is FDA-approved for type 2 diabetes and chronic weight management, and includes semaglutide, liraglutide, dulaglutide, and exenatide.
In Depth
GLP-1 receptor agonists are a class of medications that bind to and activate the GLP-1 receptor, mimicking the action of the body's endogenous glucagon-like peptide-1 hormone. Endogenous GLP-1 is released from intestinal L cells in response to food intake.
The shared pharmacological effects of GLP-1 receptor agonists include:
- Slowing gastric emptying (food remains in the stomach longer, producing prolonged satiety). - Glucose-dependent insulin release (insulin rises only when blood glucose is elevated, reducing hypoglycemia risk vs other diabetes medications). - Suppression of glucagon when glucose is elevated. - Modulation of central appetite signaling at the hypothalamus.
The class includes:
- Semaglutide (Ozempic, Wegovy, Rybelsus). Once-weekly subcutaneous; oral daily formulation. - Liraglutide (Victoza, Saxenda). Once-daily subcutaneous. - Dulaglutide (Trulicity). Once-weekly subcutaneous. - Exenatide (Byetta, Bydureon). Twice-daily or once-weekly subcutaneous. - Lixisenatide (Adlyxin). Once-daily subcutaneous.
Tirzepatide is a closely related but pharmacologically distinct molecule — a dual GIP/GLP-1 receptor agonist, not a pure GLP-1 receptor agonist.
The class shares a common safety profile: gastrointestinal side effects predominate, with rare but serious risks of pancreatitis, gallbladder disease, and a labeled warning regarding rodent thyroid C-cell tumors. Personal or family history of medullary thyroid carcinoma or MEN2 is a contraindication.
The diabetes evidence base for GLP-1 receptor agonists includes cardiovascular outcome data (notably the LEADER trial for liraglutide and the SUSTAIN-6 trial for semaglutide). The weight management evidence comes from the STEP trials for semaglutide and the SCALE trials for liraglutide.
Related Terms
Tirzepatide
Tirzepatide is a dual glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist administered by weekly subcutaneous injection. The FDA approved tirzepatide for type 2 diabetes management in 2022 under the brand name Mounjaro, and for chronic weight management in adults with obesity or overweight with weight-related comorbidities in 2023 under the brand name Zepbound. Compounded tirzepatide formulations, which are prepared by state-licensed compounding pharmacies pursuant to valid prescriptions, are not FDA-approved drug products and differ from the branded versions in formulation, dosing, and regulatory oversight.
Liraglutide
Liraglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist administered once daily via subcutaneous injection. The FDA approved liraglutide under the brand name Victoza for type 2 diabetes management and under the brand name Saxenda for chronic weight management in adults with obesity or overweight with at least one weight-related comorbidity. It mimics the action of naturally occurring GLP-1, a hormone that regulates blood sugar and appetite by slowing gastric emptying, enhancing insulin secretion, and reducing glucagon release. Compounded liraglutide formulations, which may be available through telehealth pharmacies like ZYNDIO, are not FDA-approved drug products and are prepared by state-licensed compounding pharmacies pursuant to a valid prescription from a licensed provider.
Semaglutide
Semaglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist FDA-approved for type 2 diabetes (Ozempic, Rybelsus) and chronic weight management (Wegovy). It is administered as a once-weekly subcutaneous injection or as a daily oral tablet, and acts by slowing gastric emptying, increasing satiety signaling, and improving glucose-dependent insulin secretion.