GLP-1 and metabolic medicine

Liraglutide

Also called: Saxenda, Victoza

Liraglutide is a GLP-1 receptor agonist taken as a daily injection. It is the active drug in Victoza (for type 2 diabetes) and Saxenda (for weight management). It was the first GLP-1 medication approved for weight loss, but weekly newer drugs (semaglutide, tirzepatide) have largely replaced it in new prescriptions because they produce more weight loss with less injecting.

What it does

Liraglutide mimics GLP-1, a hormone the gut releases after meals. It prompts the pancreas to release insulin, slows the rate at which food leaves the stomach, and signals fullness to the brain. Same mechanism as semaglutide, just a much shorter-acting molecule.

Brands

  • Victoza: 1.2 mg or 1.8 mg daily, licensed for type 2 diabetes.
  • Saxenda: up to 3 mg daily, licensed for weight management.
  • Generic liraglutide: now available in some markets after the patent expired.

Liraglutide vs semaglutide

  • Schedule: liraglutide daily, semaglutide weekly.
  • Half-life: liraglutide ~13 hours, semaglutide ~7 days.
  • Average weight loss in trials: 8 percent for liraglutide 3 mg vs 15 percent for semaglutide 2.4 mg.
  • Diabetes blood sugar control: in head-to-head trials semaglutide lowered HbA1c more than liraglutide (SUSTAIN 10), though oral semaglutide was non-inferior to the maximum 1.8 mg liraglutide dose (PIONEER 4).
  • Cost: liraglutide is now the cheaper option in some markets, especially in generic form.

Side effects

  • Nausea, especially in the first month and after each dose increase.
  • Constipation. Slowed gut transit is part of the mechanism.
  • Diarrhoea in a smaller subset, often early.
  • Reflux, burping.
  • Injection-site reactions are more common with daily injecting.
  • Rare but serious: pancreatitis, gallstones, severe gastroparesis.

Why it's still used

Liraglutide has one of the longest post-launch safety records of any GLP-1 drug, behind only exenatide. It is sometimes preferred when supply of weekly options is unstable, when generic pricing brings the cost down, or when a clinician wants the shorter half-life for taper flexibility. Some patients also tolerate the smaller daily peak better than the weekly peak and trough of semaglutide.

Common questions

Is liraglutide the same as semaglutide?
Same drug class (GLP-1 agonists), different molecules. Liraglutide is shorter-acting and dosed daily. Semaglutide is longer-acting and dosed weekly. Semaglutide produces more weight loss in trials.
Is generic liraglutide as good as branded?
In principle yes, regulatory approval requires bioequivalence. The active drug is identical. Real-world data on generics is still accumulating because they only became available recently.
Why does liraglutide cause nausea more than semaglutide for some people?
The daily peak hits the gut hormone receptors more sharply than the slow weekly rise of semaglutide. Some people find this tolerable, others don't. It's genuinely individual.
Can children take liraglutide?
Yes, in specific cases. Saxenda is approved for adolescents (12 to 17) with obesity and over 60 kg, accessed through specialist paediatric services. Use is rare and supervised.

Sources

The Book of Suna is general information, not medical advice. It is not a substitute for talking to a qualified healthcare professional about your own situation.