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The dad-test answer
Both are made by Novo Nordisk, both are GLP-1 agonists. Saxenda (liraglutide) is the older daily injection; Ozempic and Wegovy (semaglutide) are the newer once-weekly version. STEP-8 head-to-head: semaglutide produced 15.8% weight loss at 68 weeks vs 6.4% on liraglutide - a 2.5x gap. Semaglutide wins on weight loss, A1C, and adherence (weekly vs daily). Saxenda is older, sometimes cheaper, and the daily-injection cadence is what some patients prefer.
Who wins for what
| Use case | Who wins, and why |
|---|---|
| weight loss in adults without diabetes |
semaglutide (wegovy) STEP-8 head-to-head: 15.8% body-weight loss on semaglutide 2.4mg vs 6.4% on liraglutide 3.0mg at 68 weeks. |
| A1C reduction in Type 2 diabetes |
semaglutide (ozempic) Semaglutide reduces A1C more than liraglutide at standard doses across head-to-head trials. |
| dosing convenience |
semaglutide Once-weekly injection vs daily; 52 injections/year vs 365 - meaningful adherence difference. |
| older / longer real-world record |
liraglutide Saxenda (Victoza in diabetes) approved by FDA in 2010-2014; semaglutide approved 2017-2021 - liraglutide has more years of post-market data. |
What the head-to-head data shows
Both are FDA-approved Novo Nordisk GLP-1 receptor agonists. Liraglutide was approved as Victoza for Type 2 diabetes in 2010 and as Saxenda for chronic weight management in 2014. Semaglutide was approved as Ozempic for Type 2 diabetes in 2017 and as Wegovy for chronic weight management in 2021. The pivotal liraglutide-for-weight-loss trial is Pi-Sunyer et al., NEJM 2015 (SCALE Obesity and Prediabetes): 3,731 patients, 56 weeks, average weight loss 8.4 kg on liraglutide 3.0mg vs 2.8 kg on placebo (about 8% body-weight loss). The pivotal semaglutide trial is STEP-1 (Wilding et al., NEJM 2021): 14.9% body-weight loss at 68 weeks. The head-to-head is STEP-8 (Rubino et al., JAMA 2022): semaglutide 2.4mg weekly vs liraglutide 3.0mg daily for 68 weeks - mean weight loss 15.8% vs 6.4%, a 2.5x gap that closed any remaining question about relative efficacy. Both molecules carry the standard GLP-1 black-box warning for thyroid C-cell tumors.
Our honest call
For new starters in 2026, semaglutide is the clear default - 2.5x more weight loss in a clean head-to-head trial and a once-weekly injection vs daily. There is no meaningful efficacy reason to start liraglutide first if semaglutide is available. Saxenda (and Victoza) remain reasonable choices when insurance only covers the older liraglutide formulary, when the patient has a specific reason to prefer daily injection, or when the patient has tolerated liraglutide well for years and switching has no upside. The most common reason patients land on Saxenda in 2026 is access friction with the newer molecules - that's a coverage problem, not a clinical one. Read the GLP-1 starter guide and the tirzepatide vs semaglutide page for the broader picture.
Sources and citations
- Rubino et al., STEP-8 head-to-head trial, JAMA 2022 (PMID 35015037)
- Pi-Sunyer et al., SCALE liraglutide trial, NEJM 2015 (PMID 26132939)
- Wilding et al., STEP-1 trial, NEJM 2021 (PMID 33567185)
- FDA Saxenda prescribing label (approved Dec 2014)
- FDA Ozempic prescribing label (approved Dec 2017)
- FDA Wegovy prescribing label (approved Jun 2021)
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Last reviewed · 2026-05-07 · Page generated by Protocol One matrix engine. None of this replaces a doctor. Peptides are gray-market in the US for most uses. Talk to a real prescriber before you change anything.