What the human research shows
Grade A across the board because the trials are large, published and consistent. The story since 2021 is one of relative decline: semaglutide and tirzepatide roughly double its weight effect, so its role is shifting to price, paediatrics and people who cannot tolerate the weekly drugs.
| Outcome | Grade | Effect size | Human studies | Where the evidence comes from |
|---|---|---|---|---|
| Body weight (adults) | AEstablished | Moderate | 5 SCALE RCTs | SCALE Obesity and Prediabetes, 3,731 adults, 56 weeks: −8.0% on liraglutide 3.0 mg versus −2.6% on placebo; 63% versus 27% lost at least 5%, 33% versus 11% at least 10%.1 |
| Major cardiovascular events | AEstablished | Small | 1 large outcome RCT | LEADER, 9,340 people with type 2 diabetes, median 3.8 years: MACE 13.0% versus 14.9% (hazard ratio 0.87, 95% CI 0.79–0.97); cardiovascular death HR 0.78; all-cause death HR 0.85.2 |
| Blood glucose (HbA1c) | AEstablished | Moderate | LEAD programme, 6 RCTs | The original approval basis (Victoza, 2009–2010): HbA1c reductions of roughly 1–1.5 percentage points across the LEAD trials.3 |
| Body weight (adolescents 12–17) | AEstablished | Small | 1 RCT | SCALE Teens, 251 adolescents, 56 weeks: BMI standard-deviation score −0.23 versus −0.00; the first GLP-1 approval for under-18s.4 |
| Body weight (children 6–11) | BProbable | Moderate | 1 RCT | SCALE Kids, 82 children, 56 weeks: BMI −5.8% versus +1.6% on placebo. One small trial; not yet a licensed indication in most jurisdictions.5 |
| GI side effectsadverse | AEstablished | Large | All trials | Nausea in roughly 40% at the 3.0 mg dose in SCALE, vomiting and diarrhoea common; about 10% stopped for adverse events versus 4% on placebo.1 |
| Gallbladder eventsadverse | AEstablished | Small | SCALE + LEADER | Cholelithiasis and cholecystitis were more frequent on liraglutide (2.5% versus 1.0% in SCALE), a class effect partly explained by rapid weight loss.12 |
Literature searched to 3 September 2026. Human studies only; animal and cell work informs the mechanism section and nothing else.
What it is
A GLP-1 analogue with a fatty-acid side chain that binds albumin, stretching the hormone's minutes-long half-life to about 13 hours — long enough for once-daily injection. Approved as Victoza for type 2 diabetes (2009 EU, 2010 US) and as Saxenda for obesity at a higher dose (2014–2015).
Patent expiry brought generic liraglutide to the US in 2024 (Victoza) and 2025 (Saxenda), making it the cheapest GLP-1 drug by a wide margin and, for many health systems, the first-line option.
How it is thought to work
Activates GLP-1 receptors in the pancreas (more insulin, less glucagon after meals), the stomach (slower emptying) and the hypothalamus and brainstem (less appetite). The weight effect is mostly appetite; the glucose effect mostly pancreatic.
Because it is dosed daily and its peak is shorter, the weight loss is roughly half that of semaglutide in head-to-head comparison (STEP 8: 15.8% versus 6.4% at 68 weeks).
What is still unknown
- Long-term outcomes in children on the drug for years.
- How much of the cardiovascular benefit in LEADER transfers to people without diabetes — the equivalent trial was run with semaglutide, not liraglutide.
Regulatory status
Victoza (2009) and Saxenda (2015) authorised via the EMA; generics authorised from 2024.
Victoza (2010), Saxenda (2014); first generic liraglutide launched 2024. Compounded copies are not permitted now that approved generics exist.
Victoza and Saxenda licensed; Saxenda available on the NHS through specialist weight-management services.
Victoza and Saxenda on the ARTG. Compounded GLP-1 copies unlawful since 1 October 2024.
Victoza and Saxenda carry a DIN.
Not on the 2026 Prohibited List.
Questions people actually ask
Is liraglutide as good as semaglutide for weight loss?
Does liraglutide protect the heart?
Is there a generic?
Can children take it?
One page per claimed effect
- ADoes Liraglutide help with body weight?5 SCALE RCTs
- ADoes Liraglutide help with major cardiovascular events?1 large outcome RCT
- ADoes Liraglutide help with blood glucose?LEAD programme, 6 RCTs
- ADoes Liraglutide help with body weight?1 RCT
- BDoes Liraglutide help with body weight?1 RCT
- AHow common is GI side effects with Liraglutide?All trials
- AHow common is gallbladder events with Liraglutide?SCALE + LEADER
References
- 1Pi-Sunyer X, et al. A randomized, controlled trial of 3.0 mg of liraglutide in weight management (SCALE Obesity and Prediabetes).N Engl J Med, 2015; DOI 10.1056/NEJMoa14118923,731 adults, 56 weeks.
- 2Marso SP, et al. Liraglutide and cardiovascular outcomes in type 2 diabetes (LEADER).N Engl J Med, 2016; DOI 10.1056/NEJMoa16038279,340 patients, median 3.8 years.
- 3Liraglutide (Victoza) prescribing information and the LEAD trial programme.FDA labelHbA1c data from six phase 3 trials.
- 4Kelly AS, et al. A randomized, controlled trial of liraglutide for adolescents with obesity (SCALE Teens).N Engl J Med, 2020; DOI 10.1056/NEJMoa1916038251 adolescents, 56 weeks.
- 5Fox CK, et al. Liraglutide for children 6 to <12 years of age with obesity (SCALE Kids).N Engl J Med, 2024; DOI 10.1056/NEJMoa240737982 children, 56 weeks.
Change log
- 2026-09-03Initial publication from the SCALE, LEADER and paediatric trials.