Wegovy vs Saxenda: Which GLP-1 Is Right for You?
Wegovy and Saxenda are both GLP-1 receptor agonists approved for weight management, but they differ significantly in efficacy, dosing convenience, and mechanism. This comprehensive guide compares their clinical data, side effects, cost, and real-world outcomes to help you make an informed decision with your healthcare provider.
Quick Comparison Table
| Feature | Wegovy | Saxenda |
|---|---|---|
| Active Ingredient | Semaglutide | Liraglutide |
| Dosing | Weekly injection (2.4mg) | Daily injection (3mg) |
| Avg Weight Loss | 15-18% body weight | 5-6% body weight |
| Half-Life | ~7 days | ~13 hours |
| Monthly Cost | $1,200-1,500 | $900-1,200 |
| FDA Approval | Nov 2021 | Dec 2014 |
| Primary Action | GLP-1 Receptor Agonist | GLP-1 Receptor Agonist |
Mechanism of Action: How They Work Differently
While both Wegovy and Saxenda are GLP-1 receptor agonists, they are distinct molecules with different pharmacological profiles that influence their efficacy and tolerability.
Wegovy (Semaglutide)
Semaglutide is a human GLP-1 receptor agonist analog with 94% structural homology to native GLP-1. It demonstrates superior receptor selectivity and has a much longer half-life (~7 days) due to its fatty acid side chain that allows binding to albumin. This extended duration enables once-weekly dosing at higher therapeutic concentrations.
Saxenda (Liraglutide)
Liraglutide is a human GLP-1 receptor agonist analog with 97% structural homology to native GLP-1. It has a shorter half-life (~13 hours), requiring daily injections. While highly specific for GLP-1 receptors, its shorter duration limits peak concentration compared to semaglutide, which may explain reduced efficacy in weight loss trials.
Key Insight: Both drugs stimulate appetite suppression, slow gastric emptying, and increase satiety through the same GLP-1 pathway, but semaglutide's longer half-life and superior binding profile allow for higher sustained receptor activation.
Clinical Efficacy: STEP vs SCALE Trials
The most significant difference between these medications is demonstrated in their pivotal clinical trials, which show substantially different weight loss outcomes.
Wegovy: STEP Trials (Semaglutide)
- STEP 1: 15.3 kg average weight loss (13.6% body weight) at 2.4mg weekly over 68 weeks
- STEP 2: 10.4 kg average weight loss (9.2%) after regain post-discontinuation
- STEP 3 (Diabetes): 5.7-7.3 kg average weight loss; significant HbA1c reduction
- STEP 4 (Maintenance): Sustained weight loss with continued dosing; 65% of patients lost ≥10% body weight
Saxenda: SCALE Trials (Liraglutide)
- SCALE Obesity: 5.9 kg average weight loss (5.1% body weight) at 3mg daily over 56 weeks
- SCALE Diabetes: 2.9 kg average weight loss; improved glycemic control but modest weight reduction
- Responder rate: ~56% of patients achieved ≥5% weight loss vs 85% with Wegovy at 2.4mg
Clinical Significance: Wegovy demonstrates approximately 2.5-3x greater weight loss compared to Saxenda in head-to-head comparative analyses. This superior efficacy has driven Wegovy's rapid adoption despite higher cost.
Dosing & Administration Schedules
Wegovy (Weekly)
- Week 1-4: 0.25mg once weekly
- Week 5-8: 0.5mg once weekly
- Week 9-12: 1mg once weekly
- Week 13-16: 1.7mg once weekly
- Week 17+: 2.4mg once weekly (maintenance dose)
Saxenda (Daily)
- Day 1-6: 0.6mg once daily
- Day 7-12: 1.2mg once daily
- Day 13-18: 1.8mg once daily
- Day 19-24: 2.4mg once daily
- Day 25+: 3.0mg once daily (maintenance dose)
Convenience Factor: Wegovy requires only 4 injections per month, while Saxenda requires 30 daily injections. For patients who dislike frequent injections, Wegovy's weekly schedule offers significant convenience advantage. However, Saxenda's daily dosing allows for more flexible dose adjustments if side effects occur.
Cost & Insurance Coverage
Wegovy
- List Price: $1,300-1,500/month
- With Insurance: $0-500/month (varies)
- Copay Assistance: Novo Nordisk offers savings cards up to $500/month
- Tier Status: Often Tier 3-4 (specialty tier)
Saxenda
- List Price: $900-1,200/month
- With Insurance: $0-350/month (varies)
- Copay Assistance: Eli Lilly assistance programs available
- Tier Status: Often Tier 2-3 (lower than Wegovy)
Saxenda is generally 20-30% less expensive than Wegovy at list price. However, many insurance plans now cover both medications, making actual out-of-pocket costs similar. Manufacturer copay assistance programs are available for both, frequently reducing patient costs to $0-200/month for eligible individuals.
Side Effects & Tolerability
| Side Effect | Wegovy | Saxenda |
|---|---|---|
| Nausea | 25-35% | 20-30% |
| Vomiting | 10-15% | 5-10% |
| Diarrhea | 20-25% | 15-20% |
| Constipation | 15-20% | 10-15% |
| Headache | 5-10% | 5-10% |
| Pancreatitis (Rare) | <0.1% | <0.1% |
Both medications share the same primary adverse effects due to GLP-1 pathway activation. Gastrointestinal side effects are most common and typically improve after 4-12 weeks as the body adapts. Saxenda's slightly lower GI side effect rates may reflect lower effective doses or dosing frequency allowing more tolerance development.
Managing Side Effects
- Saxenda: Daily dosing allows gradual titration and flexible timing; can take with food to reduce nausea
- Wegovy: Weekly dosing concentrates effects; cannot split doses; dietary modifications essential
- Both: Slow uptitration, dietary adjustments (smaller meals, avoid fatty foods), adequate hydration, and ginger supplements may help
Which Is Better? When to Choose Each
Choose Wegovy If You:
- Want maximum weight loss efficacy (15-18% vs 5-6% body weight)
- Prefer once-weekly injections over daily injections
- Have failed previous weight loss attempts and need stronger medication
- Can afford higher upfront costs (though insurance/assistance may equalize)
- Need sustained, significant weight loss for health conditions (severe obesity, metabolic syndrome)
Choose Saxenda If You:
- Are concerned about injection frequency and prefer gradual daily dosing
- Want lower cost at baseline (before insurance)
- Need flexibility to adjust doses daily if side effects occur
- Have mild-to-moderate obesity requiring 5-10% weight loss
- Prefer an established medication (FDA approved 2014) with longer real-world data
Bottom Line: Wegovy is superior for significant weight loss outcomes but requires weekly commitment. Saxenda is simpler to titrate and slightly cheaper but offers modest results. For most patients seeking substantial weight loss, Wegovy is the more effective choice despite higher cost.
Frequently Asked Questions
Wegovy (semaglutide) at 2.4mg shows average weight loss of 15-18% body weight in STEP trials, while Saxenda (liraglutide) at 3mg shows approximately 5-6% body weight loss in SCALE trials. Wegovy is significantly more effective for weight loss outcomes.
Switching between these medications requires medical supervision. Due to different potencies and dosing schedules, your doctor must design a transition protocol. You cannot directly convert dosages due to different pharmacokinetics and molecular structures.
Both cause similar GLP-1 side effects (nausea, vomiting, diarrhea, constipation). Saxenda with daily dosing may allow for more flexible timing adjustments. Wegovy's weekly dosing concentrates effects but may provide less opportunity for dose spacing adjustments.
Efficacy differences stem from molecular structure (semaglutide vs liraglutide), dosing frequency (weekly vs daily), and receptor selectivity. Semaglutide has superior GLP-1 receptor binding and longer half-life, allowing higher therapeutic doses.
Wegovy is FDA-approved specifically for weight management in obese/overweight patients. Ozempic (semaglutide) is the diabetes version. Saxenda is approved for chronic weight management only. Different formulations exist for different indications.
Weight regain typically occurs within months if diet and exercise aren't maintained. Studies show approximately 50% weight regain within 1 year post-discontinuation for both medications. Long-term therapy is often necessary for sustained results.