Wegovy vs Saxenda: the head-to-head wasn't close
Both are weight-loss GLP-1 injections, but in STEP 8 the newer once-weekly Wegovy produced ~15.8% weight loss versus ~6.4% for the daily Saxenda — and was more convenient too.
Wegovy versus Saxenda is one of the more lopsided GLP-1 comparisons — and, usefully, it was settled by a head-to-head trial designed specifically to measure weight loss. The newer, once-weekly drug roughly doubled the older, daily one. Here’s the evidence and the few situations where Saxenda still comes up.
Two weight-loss GLP-1 drugs, a generation apart
Both are GLP-1 receptor agonists approved for chronic weight management, but they’re different molecules from different eras. Saxenda (liraglutide 3.0 mg) is the older drug, taken as a daily injection. Wegovy (semaglutide 2.4 mg) is the newer, longer-acting molecule, taken once weekly. The clinical question is simply how much that generational gap is worth.
The head-to-head: STEP 8
STEP 8 was a 68-week randomized trial in 338 adults with overweight or obesity (without diabetes), with percentage weight loss as the primary endpoint — the cleanest kind of comparison. Wegovy produced a mean weight loss of 15.8%, versus 6.4% for Saxenda and 1.9% for placebo — a 9.4-percentage-point advantage for Wegovy (p<0.001).[1]
- Wegovy (semaglutide 2.4 mg)15.8%
- Saxenda (liraglutide 3.0 mg)6.4%
- Placebo1.9%
The gap was just as stark at the thresholds people care about. The share of patients who lost at least 15% of their body weight was 55.6% on Wegovy versus 12.0% on Saxenda; for a 20% loss, it was 38.5% versus 6.0%.[1] More than half of Wegovy users hit a milestone barely one in eight Saxenda users reached.
−15.8%
Wegovy mean weight loss
STEP 8
−6.4%
Saxenda mean weight loss
STEP 8
55.6% vs 12%
Reached ≥15% weight loss
STEP 8
| Wegovy (semaglutide) | Saxenda (liraglutide) | |
|---|---|---|
| Dosing | Once weekly injection | Once daily injection |
| Mean weight loss (STEP 8) | −15.8% | −6.4% |
| Reached ≥15% loss | 55.6% | 12.0% |
| Generation | Newer, longer-acting | Older, shorter-acting |
| Approved for | Weight management | Weight management |
The honest verdict
This one isn’t close: in the trial built to compare them, Wegovy produced about 2.5 times the weight loss of Saxenda while also being more convenient (weekly versus daily).[1]Saxenda retains niche roles — adolescents, coverage quirks, familiarity — but on the core question of effectiveness, Wegovy is the stronger choice. For how Wegovy stacks up against the tirzepatide brand, see Zepbound vs Wegovy; for the cost picture, Wegovy cost; and for routes to a prescription, our GLP-1 provider guide.
Reviewed against primary sources by the Aminoscope desk
Sources
- [1] Rubino DM, Greenway FL, Khalid U, et al. (2022). Effect of Weekly Subcutaneous Semaglutide vs Daily Liraglutide on Body Weight in Adults With Overweight or Obesity Without Diabetes: The STEP 8 Randomized Clinical Trial. JAMA. PMID 35015037
Related tool
GLP-1 weight-loss comparison
See semaglutide, tirzepatide, retatrutide and the pipeline ranked by mean trial weight loss — every figure traced to its source.