Liraglutide

Think of liraglutide as the reliable, well-tested family car of weight-loss medicines. It has a long service history and crash-test data (large trials, regulatory approval). It gets you there, but the newer weekly models (semaglutide, tirzepatide) are faster and need refuelling far less often, which is why most drivers have switched.

Liraglutide is a GLP-1 receptor agonist that binds the GLP-1 receptor and reproduces the actions of the native incretin hormone GLP-1: glucose-dependent enhancement of insulin secretion, suppression of glucagon, delayed gastric emptying, and central appetite suppression via hypothalamic pathways. A palmitoyl fatty-acid modification promotes albumin binding and slows degradation, extending the half-life sufficiently for once-daily subcutaneous injection.

Research contexts. Not proven uses, and not recommendations.

Extensive. Multiple large, randomised, placebo-controlled human trials underpin its approvals. The SCALE Obesity and Prediabetes RCT (~3,700 adults, NEJM 2015) established weight-management efficacy with placebo-subtracted weight loss of approximately 5–6 percent of body weight over 56 weeks. The LEADER trial (~9,300 patients, NEJM 2016) demonstrated reduced major adverse cardiovascular events in type 2 diabetes with high cardiovascular risk. Head-to-head data (STEP 8, JAMA 2022) show liraglutide produces clearly less weight loss than once-weekly semaglutide. This is genuine, high-quality human evidence, not extrapolation from animal data.

• !Common gastrointestinal side effects: nausea, vomiting, diarrhoea, constipation, especially during dose escalation
• !Risk of acute pancreatitis and increased gallbladder events including cholelithiasis
• !Class warning for rodent thyroid C-cell tumours; contraindicated in personal or family history of medullary thyroid carcinoma or MEN2
• !Less effective for weight loss than newer agents (semaglutide, tirzepatide) and requires daily rather than weekly injection
• !Risk of hypoglycaemia when combined with insulin or sulfonylureas
• !Grey-market and unlicensed 'research chemical' versions exist; only pharmacy-supplied, prescribed product has assured identity, purity and dose

A licensed, prescription-only medicine (POM) in the UK, regulated by the MHRA. It is marketed as Victoza for type 2 diabetes and as Saxenda for weight management in adults with obesity (or overweight with a weight-related comorbidity) and in adolescents aged 12 and over. Following UK patent expiry in late 2024, lower-cost generic versions such as Nevolat have entered the market. It must be obtained on prescription. Products sold online as unlicensed 'research chemicals' are illegitimate and unregulated.

• NCT01272219· Phase 3· Completed

  SCALE Obesity and Prediabetes

  Pivotal weight-management efficacy trial; published NEJM 2015.

• NCT01179048· Phase 3b· Completed

  LEADER - Liraglutide Effect and Action in Diabetes: Evaluation of Cardiovascular Outcome Results

  Demonstrated cardiovascular benefit in type 2 diabetes with high cardiovascular risk; NEJM 2016.

• NCT04074161· Phase 3b· Completed

  STEP 8 - once-weekly semaglutide vs once-daily liraglutide for weight loss

  Showed greater weight loss with once-weekly semaglutide than daily liraglutide; JAMA 2022.

1. 01
   A Randomized, Controlled Trial of 3.0 mg of Liraglutide in Weight Management (SCALE Obesity and Prediabetes) — Pi-Sunyer X, Astrup A, Fujioka K, et al., New England Journal of Medicine (2015)

   Pivotal RCT establishing weight-management efficacy; ~5.6 kg placebo-subtracted loss at 56 weeks. NCT01272219.

2. 02
   Liraglutide and Cardiovascular Outcomes in Type 2 Diabetes (LEADER) — Marso SP, Daniels GH, Brown-Frandsen K, et al., New England Journal of Medicine (2016)

   Cardiovascular outcomes trial showing reduced 3-point MACE in type 2 diabetes with high cardiovascular risk. NCT01179048.

3. 03
   A Randomized, Controlled Trial of Liraglutide for Adolescents with Obesity — Kelly AS, Auerbach P, Barrientos-Perez M, et al., New England Journal of Medicine (2020)

   56-week RCT supporting the adolescent (12+) weight-management indication.

4. 04
   Effect of Weekly Subcutaneous Semaglutide vs Daily Liraglutide on Body Weight in Adults With Overweight or Obesity Without Diabetes (STEP 8) — Rubino DM, Greenway FL, Khalid U, et al., JAMA (2022)

   Head-to-head RCT; weekly semaglutide produced significantly greater weight loss than daily liraglutide at 68 weeks.

5. 05
   MHRA / EMA Saxenda and Victoza (liraglutide) summaries of product characteristics, Medicines and Healthcare products Regulatory Agency (2024)

   UK regulatory status, indications and prescribing information for Saxenda and Victoza.