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AMIRAVOResearch Library

Liraglutide vs tirzepatide

Liraglutide and tirzepatide are both FDA-approved incretin-based peptides: liraglutide (Victoza, Saxenda) is a GLP-1 receptor agonist approved since 2010, and tirzepatide (Mounjaro, Zepbound) is a dual GIP and GLP-1 receptor agonist approved since 2022 1,2,3. Their labels differ in half-life, about 13 hours for liraglutide and about 5 days for tirzepatide 3,4. No randomized trial comparing them directly was identified; a registered observational cohort study is comparing them on bone markers 5,6.

Unbranded reference vial illustrating Liraglutide; not an actual product
Liraglutide
FDA-approved
Unbranded reference vial illustrating Tirzepatide; not an actual product
Tirzepatide
FDA-approved

Side by side

FieldLiraglutideTirzepatide
ClassGLP-1 receptor agonist 2Dual GIP receptor and GLP-1 receptor agonist 3
Origin and structureGLP-1 analogue with 97% homology to human GLP-1, made by recombinant expression in yeast and acylated with a C16 palmitic acid on lysine 26 2Synthetic peptide based on the GIP sequence with a C20 fatty diacid attached at lysine 20 3
Proposed mechanismBinds and activates the GLP-1 receptor and resists breakdown by DPP-4 and neutral endopeptidases 2Binds and activates GIP and GLP-1 receptors; glucose-dependent insulin secretion and lower glucagon 3
Half-lifeAbout 13 hours; the Saxenda label describes it as suitable for once-daily administration 2,4About 5 days (Mounjaro); about 5 to 6 days in overweight or obesity (Zepbound) 3,7
Highest human trial phaseApproved; phase 3 and cardiovascular outcome trials published 8,9Approved; phase 3 programme published 10,11
FDA statusApproved as Victoza (25 January 2010) and Saxenda (23 December 2014), per Drugs@FDA as of 24 October 2026 1Approved as Mounjaro (13 May 2022) and Zepbound (8 November 2023), per Drugs@FDA as of 24 October 2026 1
Published human outcomesSCALE: mean change of -8.4 kg vs -2.8 kg with placebo at 56 weeks 8; LEADER: cardiovascular events hazard ratio 0.87 in type 2 diabetes 9SURMOUNT-1: -15.0% to -20.9% vs -3.1% with placebo at 72 weeks 10; SURMOUNT-OSA: lower apnea-hypopnea index 11
Safety signalsBoxed warning for thyroid C-cell tumours in rats and mice; label warnings include heart-rate increase; gastrointestinal reactions most common 2Boxed warning for thyroid C-cell tumours in rats; gastrointestinal reactions most common 3
WADA statusNot named on the 2026 Prohibited List 12; WADA said GLP-1 receptor agonist status is unchanged for 2027 13Not named on the 2026 Prohibited List 12; GLP-1 receptor agonist status, including tirzepatide, unchanged for 2027 13
Who funded the evidenceNovo Nordisk (SCALE); Novo Nordisk and the US National Institutes of Health (LEADER) 8,9Eli Lilly 10,11

Liraglutide: what the data says

Liraglutide is approved for type 2 diabetes and cardiovascular risk reduction (Victoza) and for chronic weight management in adults and in pediatric patients aged 12 and over with obesity and body weight above 60 kg (Saxenda) 2,4.

  • In SCALE Obesity and Prediabetes (3731 adults without diabetes; human data), participants on liraglutide lost a mean of 8.4 kg vs 2.8 kg on placebo at 56 weeks; 63.2% vs 27.1% lost at least 5% of body weight 8.
  • In LEADER (9340 people with type 2 diabetes at high cardiovascular risk; human data), the primary cardiovascular outcome occurred in 13.0% vs 14.9% with placebo (hazard ratio 0.87) 9.

Tirzepatide: what the data says

Tirzepatide is approved for type 2 diabetes and cardiovascular risk reduction in high-risk adults with type 2 diabetes (Mounjaro) and for chronic weight management and obstructive sleep apnea in adults with obesity (Zepbound) 3,7.

  • In SURMOUNT-1 (2539 adults without diabetes; human data), mean body-weight change at 72 weeks was -15.0% to -20.9% vs -3.1% with placebo 10.
  • In SURMOUNT-OSA (human data), the apnea-hypopnea index fell by 20.0 and 23.8 more events per hour than with placebo in two trials 11.

Key research differences

  • Receptor targets: liraglutide acts on the GLP-1 receptor only, while tirzepatide also activates the GIP receptor 2,3.
  • Half-life: about 13 hours for liraglutide vs about 5 days for tirzepatide, per their labels 3,4.
  • Approval history: liraglutide was first approved in 2010 and tirzepatide in 2022 1.
  • Label-listed indications: Zepbound includes obstructive sleep apnea in adults with obesity, and Saxenda includes pediatric patients aged 12 and over 2,7.
  • Direct comparison: no randomized head-to-head trial was identified; one observational cohort study comparing their effects on bone turnover markers is recruiting 5,6.

Where the evidence is limited

No randomized trial comparing liraglutide and tirzepatide was found in the registry search reviewed 5. SCALE and SURMOUNT-1 differed in duration (56 vs 72 weeks), era and reporting (kilograms vs percent change), so their results cannot be ranked 8,10. Each drug's main trials were funded by its manufacturer 8,10.

Frequently asked questions

Does tirzepatide lead to more body-weight change than liraglutide?
No head-to-head randomized trial was identified, so the evidence reviewed cannot answer this. Their main trials differ in duration, period and how results were reported 5,8,10.
Why is liraglutide given daily and tirzepatide weekly?
The labels report a half-life of about 13 hours for liraglutide and about 5 days for tirzepatide, which the labels link to once-daily and once-weekly use respectively 2,3.
Are both FDA-approved?
Yes. Liraglutide was approved as Victoza in 2010 and Saxenda in 2014; tirzepatide as Mounjaro in 2022 and Zepbound in 2023 1.

References

  1. Drugs@FDA application records for NDA 215866 (Mounjaro), NDA 217806 (Zepbound), NDA 209637 (Ozempic), NDA 215256 (Wegovy), NDA 022341 (Victoza) and NDA 206321 (Saxenda): original approval dates (queried 24 October 2026) Drugs@FDA (via openFDA). 2026
  2. SAXENDA (liraglutide) injection: prescribing information, DailyMed set ID 3946d389-0926-4f77-a708-0acb8153b143 (label version dated 25 February 2026) FDA label (via openFDA). 2026
  3. MOUNJARO (tirzepatide) injection: prescribing information, DailyMed set ID d2d7da5d-ad07-4228-955f-cf7e355c8cc0 (label version dated 27 August 2026) FDA label (via openFDA). 2026
  4. VICTOZA (liraglutide) injection: prescribing information, DailyMed set ID 5a9ef4ea-c76a-4d34-a604-27c5b505f5a4 (label version dated 14 October 2025) FDA label (via openFDA). 2025
  5. ClinicalTrials.gov registry search for tirzepatide AND liraglutide as interventions (17 records; no randomized head-to-head trial listed; retrieved 24 October 2026) ClinicalTrials.gov. 2026
  6. TiLi-BONE: Comparative Investigation of Changes in Body Composition and Bone Turnover Markers in People With Obesity After Treatment With Tirzepatide Versus Liraglutide, a prospective cohort study (NCT07094568), registry record ClinicalTrials.gov. 2026
  7. ZEPBOUND (tirzepatide) injection: prescribing information, DailyMed set ID 487cd7e7-434c-4925-99fa-aa80b1cc776b (label version dated 28 August 2026) FDA label (via openFDA). 2026
  8. A Randomized, Controlled Trial of 3.0 mg of Liraglutide in Weight Management (SCALE Obesity and Prediabetes) N Engl J Med. 2015
  9. Liraglutide and Cardiovascular Outcomes in Type 2 Diabetes (LEADER) N Engl J Med. 2016
  10. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1) N Engl J Med. 2022
  11. Tirzepatide for the Treatment of Obstructive Sleep Apnea and Obesity (SURMOUNT-OSA) N Engl J Med. 2024
  12. The 2026 Prohibited List - World Anti-Doping Code, as published in the Netherlands Treaty Series (Tractatenblad 2026, 25; Council of Europe Anti-Doping Convention appendix, in force 1 January 2026) Tractatenblad (Official Publications of the Kingdom of the Netherlands). 2026
  13. WADA publishes 2027 Prohibited List (news release, 21 September 2026) World Anti-Doping Agency. 2026

For research use only. Not for human or veterinary use. Not a drug, food, or dietary supplement. This page compares published research and is not medical advice or a recommendation.