GLP-1 therapy and bariatric surgery are both established treatments for obesity, with different mechanisms, durability and risk profiles. In pivotal trials, average weight loss was 14.9% with semaglutide 2.4 mg (STEP 1, 68 weeks, vs 2.4% with placebo) and 20.9% with tirzepatide 15 mg (SURMOUNT-1, 72 weeks; 22.5% in the efficacy estimand), with continued treatment. Bariatric surgery typically produces 25–35% loss through a permanent anatomic change, with a recovery period and surgical risks. Selection depends on BMI, comorbidities, prior treatment history and patient preference.
Side-by-side
| Dimension | GLP-1 therapy | Bariatric surgery |
|---|---|---|
| Average weight loss | 14.9% (semaglutide, STEP 1) to 20.9% (tirzepatide, SURMOUNT-1) | About 25–35% |
| Cost | Compounded: semaglutide $49–$169/mo, tirzepatide $86–$280/mo; brand self-pay $149–$449/mo; insurance copays vary | $15,000–$35,000 one-time, often insurance-covered (July 2026) |
| Duration | Ongoing; weight tends to return after stopping | One-time procedure with lifelong follow-up |
Compounded GLP-1s are not FDA-approved and are not the same product as Wegovy or Zepbound.
Who should pick GLP-1 therapy
Patients who want pharmacologic therapy without surgical intervention; patients who haven't reached the bariatric BMI threshold; patients who want to start a treatment trial.
Who should pick Bariatric surgery
Patients with BMI ≥40 or ≥35 with serious comorbidity who haven't responded to medical therapy; patients seeking durable weight loss without ongoing medication.
Frequently asked
Can you do both?
Yes. GLP-1 is increasingly used post-bariatric for additional weight loss or weight regain. See our post-bariatric page.
Which is more durable?
Bariatric surgery produces more durable weight loss without ongoing medication. With GLP-1 therapy, much of the lost weight tends to return after the medication is stopped (STEP 4).