Liraglutide

Liraglutide is a synthetic GLP-1 receptor agonist with 97% structural homology to endogenous human GLP-1, the incretin hormone that stimulates glucose-dependent insulin secretion, suppresses glucagon release, slows gastric emptying, and reduces appetite through central and peripheral receptor activation. Liraglutide has an elimination half-life of approximately 13 hours, enabling once-daily subcutaneous injection — in contrast to the once-weekly dosing of later GLP-1 agents such as semaglutide and tirzepatide. It was the first GLP-1 receptor agonist to receive FDA approval for both type 2 diabetes (Victoza, 2010) and chronic weight management (Saxenda, 2014), and the first in its class to demonstrate a statistically significant reduction in cardiovascular events in a large randomized outcomes trial (the LEADER trial).¹²

Liraglutide is manufactured by Novo Nordisk. It represented the foundational clinical evidence for the GLP-1 drug class in cardiovascular and metabolic medicine, much of which has since been built upon by newer agents in the class.

Victoza (liraglutide 1.8 mg):

• Adjunct to diet and exercise to improve glycemic control in adults and pediatric patients 10 years of age and older with type 2 diabetes mellitus.
• Reduction of the risk of major adverse cardiovascular events (cardiovascular death, nonfatal myocardial infarction, nonfatal stroke) in adults with type 2 diabetes and established cardiovascular disease.²

Saxenda (liraglutide 3 mg):

• Chronic weight management in adults with a BMI of ≥30 kg/m² (obesity), or ≥27 kg/m² (overweight) with at least one weight-related comorbid condition, as an adjunct to reduced-calorie diet and increased physical activity.
• Chronic weight management in pediatric patients aged 12 and older with body weight greater than 60 kg and obesity.¹

Victoza: Starting dose 0.6 mg once daily for 1 week, then increased to 1.2 mg once daily; may be further increased to 1.8 mg once daily for additional glycemic benefit.

Saxenda: Starting dose 0.6 mg once daily for 1 week, then escalated weekly in 0.6 mg increments over approximately 4 weeks to the target dose of 3 mg once daily. If the 3 mg dose is not tolerated, treatment should be discontinued — unlike some other GLP-1 agents, Saxenda does not have an approved lower maintenance dose.¹

Both are administered subcutaneously in the abdomen, thigh, or upper arm. Injection site should be rotated with each dose. Liraglutide can be administered at any time of day, independent of meals.

Subcutaneous injection.

Unopened pens: refrigerate at 36°F to 46°F (2°C to 8°C); do not freeze. After first use: store below 77°F (25°C) or refrigerated; use within 30 days. Keep away from direct heat, light, and children.¹

Boxed warning: Liraglutide causes dose-dependent and duration-dependent thyroid C-cell tumors in both male and female rats and mice. It is unknown whether liraglutide causes thyroid C-cell tumors including MTC in humans. Liraglutide is contraindicated in patients with a personal or family history of MTC or MEN 2.¹

Key warnings and considerations from the FDA labels:¹²

• Pancreatitis: Cases of fatal and nonfatal acute pancreatitis have been reported. Discontinue if suspected; do not restart if confirmed.
• Gastrointestinal effects: Nausea, vomiting, diarrhea, constipation, and abdominal pain are common, particularly during dose escalation. Most GI events are transient and diminish with continued use.
• Hypoglycemia: Liraglutide alone carries low hypoglycemia risk; risk is substantially elevated when combined with insulin or sulfonylurea agents. In the Saxenda (weight management) indication, liraglutide is not to be used in combination with other GLP-1 receptor agonists.
• Heart rate: Mean increases in resting heart rate of approximately 2–3 bpm were observed in liraglutide clinical trials; the clinical significance of this increase is uncertain, and monitoring is appropriate in patients with pre-existing tachyarrhythmia.
• Pregnancy: May cause fetal harm based on animal data. Discontinue when pregnancy is recognized or planned.¹
• Class context: While liraglutide (Saxenda) remains FDA-approved for weight management, semaglutide (Wegovy) and tirzepatide (Zepbound) have demonstrated substantially greater weight reduction in comparative and head-to-head data. Prescribing patterns reflect this: newer agents have largely displaced liraglutide in the weight management space, though liraglutide remains an option, particularly for pediatric patients.