How Wegovy Stacks Up Against Ozempic and Mounjaro
Wegovy (semaglutide 2.4 mg weekly) is a GLP-1 receptor agonist approved for chronic weight management in adults with obesity or overweight plus comorbidities. It delivers higher doses than Ozempic (semaglutide up to 2 mg weekly, approved for type 2 diabetes with cardiovascular benefits and off-label weight loss use). Mounjaro (tirzepatide, up to 15 mg weekly) is a dual GLP-1/GIP agonist approved for type 2 diabetes but widely used off-label for weight loss; Zepbound is its rebranded higher-dose version for obesity.
In head-to-head trials, tirzepatide edges out semaglutide on weight loss: patients on 15 mg tirzepatide lost 20.9% body weight at 72 weeks versus 14.9% on 2.4 mg semaglutide (SURMOUNT-5 trial, 2024).[1] Semaglutide showed 15-17% loss over 68 weeks in STEP trials.[2] Both outperform older options like phentermine (5-10% loss short-term) or liraglutide (Saxenda, ~8% loss).[3]
| Drug | Active Ingredient | Max Dose | Avg Weight Loss (1 year) | Primary Approval | Cost (30-day supply, list price) |
|------|-------------------|----------|---------------------------|------------------|---------------------------------|
| Wegovy | Semaglutide | 2.4 mg/wk | 15% | Obesity | $1,350 |
| Ozempic | Semaglutide | 2 mg/wk | 10-12% (off-label) | Diabetes | $1,000 |
| Mounjaro/Zepbound | Tirzepatide | 15 mg/wk | 20-22% | Diabetes/Obesity | $1,100-$1,300 |
| Saxenda | Liraglutide | 3 mg/day | 8% | Obesity | $1,350 |
What About Side Effects and Tolerability?
All share GI issues—nausea (44% Wegovy, 37% tirzepatide), vomiting, diarrhea—but tirzepatide has slightly higher dropout rates (up to 13% vs. 7-10% for semaglutide) due to intensity.[1][4] Semaglutide carries black-box warnings for thyroid tumors (rodent data) and pancreatitis risk. Tirzepatide adds gallbladder issues. Long-term cardiovascular benefits are proven for semaglutide (reduces events by 20% in SELECT trial); tirzepatide data is emerging.[2][5]
When Does Wegovy’s Patent Expire?
Novo Nordisk holds patents on semaglutide until 2031-2033 in the US, with formulation patents extending to 2036.[6] Eli Lilly challenges some, but no generics until mid-2030s. Tirzepatide patents run to 2035-2036; biosimilars unlikely before then due to complexity.
How Do Costs and Access Compare?
List prices are similar, but insurance coverage varies: Wegovy often requires prior authorization for obesity; Ozempic is more covered for diabetes. Compounded semaglutide (cheaper, ~$300/month) surged post-shortages but faces FDA crackdowns for safety risks like dosing errors.[7] Shortages hit all three in 2023-2024, easing in 2024.
Who Makes These and What’s the Competition Landscape?
Novo Nordisk produces Wegovy/Ozempic. Eli Lilly makes Mounjaro/Zepbound. Upcoming rivals include Viking Therapeutics' VK2735 (phase 3, oral/injectable, 15% loss in 13 weeks)[8] and Amgen's MariTide (monthly dosing, 20% loss phase 2).[9] Pfizer's danuglipron flopped on tolerability.
Can You Switch Between Them?
Patients often rotate due to shortages or side effects—semaglutide users report easier titration than tirzepatide's faster ramp-up. Consult doctors; abrupt switches risk rebound weight or GI flares. Real-world data shows 25-30% of GLP-1 users discontinue within a year, mostly for side effects/cost.[10]
[1]: NEJM: Tirzepatide vs Semaglutide (SURMOUNT-5)
[2]: NEJM: SELECT Trial
[3]: JAMA: Network Meta-Analysis
[4]: FDA Labels: Wegovy
[5]: SURPASS Trials Summary
[6]: DrugPatentWatch: Semaglutide Patents
[7]: FDA: Compounded Semaglutide Alert
[8]: Viking Therapeutics Phase 2
[9]: Amgen MariTide Phase 2
[10]: JAMA: Discontinuation Rates