Semaglutide vs Liraglutide
Two FDA-approved GLP-1 receptor agonists from the same maker, compared on weight loss, cardiovascular evidence, dosing convenience, and track record.
Both are FDA-approved GLP-1 receptor agonists with Grade A cardiovascular evidence, so this is a genuine choice between two proven drugs rather than proven versus unproven. Semaglutide produces markedly greater weight loss (~15% vs ~8%) and dosing is weekly rather than daily; liraglutide is older, dosed daily, more modest on weight, but has a long real-world track record and its own cardiovascular-outcomes proof in diabetes. On magnitude and convenience semaglutide usually wins — but the right fit is a clinical decision.
| Semaglutide | Liraglutide | |
|---|---|---|
| Mechanism | GLP-1 receptor agonist | GLP-1 receptor agonist |
| Regulatory status | FDA-approved (Ozempic, Wegovy, Rybelsus) | FDA-approved (Victoza, Saxenda); generic now available |
| Approved for | Type 2 diabetes, weight management, cardiovascular risk reduction | Type 2 diabetes, weight management, cardiovascular risk reduction |
| Best evidence (weight loss) | Grade A — ~15% mean loss at 68 wks on 2.4 mg (STEP 1) | Grade A — ~8% mean loss at 56 wks on 3.0 mg (SCALE) |
| Cardiovascular evidence | Grade A — 20% MACE reduction in obesity without diabetes (SELECT); SUSTAIN-6 in T2D | Grade A — 13% MACE reduction in high-risk type 2 diabetes (LEADER) |
| Half-life / dosing | ~7 days; weekly injection or daily oral tablet | ~13 hours; daily injection |
| Common side effects | Nausea, vomiting, diarrhea, constipation, abdominal pain | Nausea, vomiting, diarrhea, constipation, headache |
| Boxed warning | Thyroid C-cell tumors (rodent data) | Thyroid C-cell tumors (rodent data) |
How to read this comparison
This is one of the rare comparisons on the site where both compounds are fully approved, both have Grade A outcomes, and the question really is “which one,” not “does either work.” Semaglutide and liraglutide are both GLP-1 receptor agonists from the same manufacturer, and liraglutide is essentially the older, shorter-acting predecessor.
On weight loss, semaglutide is clearly ahead. STEP 1 reported about 15% mean body-weight loss on 2.4 mg at 68 weeks; liraglutide’s SCALE program reported about 8% on 3.0 mg at 56 weeks. Both are real, clinically meaningful results — but the magnitude gap is large, and it is one of the main reasons prescribing has shifted toward the newer agent.
On cardiovascular protection, both hold a strong hand — in different populations. Semaglutide’s SELECT trial showed a 20% reduction in major cardiovascular events in people with obesity but without diabetes, a landmark result, and SUSTAIN-6 established benefit in type 2 diabetes. Liraglutide’s LEADER trial showed a 13% reduction in major cardiovascular events in high-risk type 2 diabetes. Both earned cardiovascular indications; semaglutide’s evidence extends further into the non-diabetic obesity population.
On convenience, semaglutide wins again: once-weekly injection (or a daily oral tablet) versus liraglutide’s daily injection. Daily dosing is a real adherence cost for many people.
Where does that leave liraglutide? It is not obsolete. It has one of the longest real-world track records in the class, a generic is now available (a genuine cost consideration), and its daily, shorter-acting profile can be an advantage when a clinician wants a more adjustable or quickly-reversible option. The side-effect profiles are close — the same gastrointestinal-dominant pattern that eases with slow titration, and the same rodent-based thyroid boxed warning.
Both are prescription medications. Which one fits — accounting for weight-loss goals, cost, dosing preference, and medical history — is a decision to make with a clinician, not from a table.
A note on "dose"
Any doses shown here are the amounts studied in trialsor the approved label schedule — not a recommendation, and not the same thing as a dose someone reports using online. See how we separate dose language.
References
- FDA Prescribing Information — Wegovy (semaglutide)
- Wilding JPH et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1). NEJM 2021
- Pi-Sunyer X et al. A Randomized, Controlled Trial of 3.0 mg of Liraglutide in Weight Management (SCALE). NEJM 2015
- Marso SP et al. Liraglutide and Cardiovascular Outcomes in Type 2 Diabetes (LEADER). NEJM 2016