Liraglutide: The First Daily GLP-1

Liraglutide is a once-daily GLP-1 receptor agonist sold as Victoza (1.2–1.8 mg, type 2 diabetes) and Saxenda (3.0 mg, chronic weight management). It was the first long-acting GLP-1 analog approved for obesity in 2014 and produced ~8% mean weight loss over 56 weeks in the SCALE Obesity trial.

Same drug class, same mechanism. Semaglutide has a longer half-life (once-weekly vs once-daily) and produces nearly twice the weight loss in head-to-head data (~15% vs ~8% over 1+ year). Liraglutide remains useful when daily dosing is preferred, in adolescents, or when semaglutide is unavailable.

Liraglutide uses a C16 monoacyl fatty-acid modification that extends its half-life to ~13 hours via albumin binding. Semaglutide uses a C18 fatty diacid linker that pushes the half-life to ~7 days, enabling weekly dosing. The structural change came directly from learning what worked with liraglutide.

Most common: nausea, vomiting, diarrhea, constipation, and injection-site reactions — mostly mild-to-moderate and usually subside after dose escalation. Boxed warning for thyroid C-cell tumors based on rodent data; contraindicated with personal/family history of medullary thyroid carcinoma or MEN-2.

Yes, but mostly as second-line. Most new GLP-1 prescriptions now go to semaglutide or tirzepatide for better efficacy and weekly dosing. Liraglutide retains use in pediatric obesity (12+), patients who prefer daily dosing, or where supply chain constraints favor older GLP-1s.