Liraglutide vs Semaglutide — daily vs weekly GLP-1 research
Liraglutide and semaglutide are both Novo Nordisk GLP-1 receptor agonists differing primarily in pharmacokinetics. Liraglutide (Victoza for T2D, Saxenda for obesity, both 2010-era) has a half-life of ~13 hours requiring daily SC injection. Semaglutide (Ozempic for T2D 2017, Wegovy for obesity 2021, Rybelsus oral 2019) has an ~7-day half-life supporting once-weekly injection or daily oral. Direct comparative trial data (SUSTAIN-7) shows semaglutide produces larger weight loss and HbA1c reductions at comparable doses. Both target the same receptor; semaglutide's structural modifications produce stronger and longer effects.
Side-by-side
| liraglutide | semaglutide-10mg | |
|---|---|---|
| Receptor | GLP-1 receptor | GLP-1 receptor (same) |
| Half-life | ~13 hours | ~7 days |
| Dosing | Daily SC | Weekly SC (or daily oral) |
| Approval status | FDA approved 2010 (T2D), 2014 (obesity) | FDA approved 2017 (T2D), 2021 (obesity), oral 2019 |
| Brand names | Victoza, Saxenda | Ozempic, Wegovy, Rybelsus |
| Trial weight loss (16w) | ~5.4% (SCALE) | ~14.9% (STEP-1, 68w) |
| CAS number | 204656-20-2 | 910463-68-2 |
What to know
- ·Both are GLP-1 receptor agonists with the same mechanism — semaglutide just sticks around longer and at higher receptor occupancy.
- ·Semaglutide produces larger weight loss in trials (~14.9% at 68 weeks vs liraglutide ~5-8% at 56 weeks).
- ·SUSTAIN-7 (head-to-head, 40 weeks): semaglutide 1mg weekly produced larger HbA1c (-1.5% vs -1.2%) and weight (-5.6 kg vs -1.9 kg) reductions than liraglutide 1.2mg daily.
- ·Daily injection adherence is meaningfully worse than weekly in real-world data — part of semaglutide's clinical advantage.
- ·Both are research-use only on this catalogue.
Where the literature diverges
Liraglutide has the longer-running clinical track record (FDA approved 2010) including the LEADER cardiovascular outcomes trial showing CV benefit in T2D. Semaglutide has caught up on cardiovascular evidence (SUSTAIN-6, SELECT showing CV benefit in obesity without T2D — a landmark 2023 result). Newer compound but stronger and broader evidence base.
FAQ
Why is semaglutide more popular than liraglutide now?+
Once-weekly dosing dramatically improves adherence and patient acceptance. The larger magnitude of weight loss in trials is partly real pharmacology and partly reflects this adherence advantage. Liraglutide has been displaced as the dominant GLP-1 agonist by semaglutide for both T2D and obesity indications.
Is liraglutide still useful?+
In specific clinical situations — paediatric obesity (Saxenda has paediatric approval semaglutide hadn't until recently), patients who can't tolerate weekly dosing, or supply-shortage situations. Both work; semaglutide just works more.
This is a research-context comparison of compound mechanism and published trial outcomes. Not medical advice. Both compounds are research-use only when sold by Omega Grade — for in vitro laboratory investigation, not human or veterinary administration.
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