Both are GLP-1 receptor agonists; they are not the same molecule. Tirzepatide is a dual GIP/GLP-1 agonist; semaglutide is a single GLP-1 agonist. Tirzepatide produced larger average weight loss in trials, including the SURMOUNT-5 head-to-head study (20.2% vs 13.7% at 72 weeks); semaglutide has broader cardiovascular and renal outcome evidence (SELECT, FLOW).
Side-by-side
| Dimension | Semaglutide | Tirzepatide |
|---|---|---|
| Mechanism | GLP-1 receptor agonist | Dual GIP/GLP-1 receptor agonist |
| Brand products | Wegovy (weight, CV), Ozempic (type 2 diabetes) | Zepbound (weight, OSA), Mounjaro (type 2 diabetes) |
| Average weight loss (pivotal trial) | 14.9% vs 2.4% placebo (STEP 1, 68 weeks) | 20.9% at 15 mg (SURMOUNT-1, 72 weeks; 22.5% efficacy estimand) |
| Head-to-head (SURMOUNT-5) | 13.7% | 20.2% |
| Brand self-pay (October 15, 2026) | Wegovy pen $349/mo (NovoCare); Wegovy pill $149–$299/mo | Zepbound $299–$449/mo (LillyDirect) |
| Compounded (October 15, 2026 index) | $49–$169/mo across 22 programs (median $94) | $86–$280/mo across 28 programs (median $144) |
Compounded semaglutide and tirzepatide are made with the drug in Wegovy or Zepbound, but they are not FDA-approved and are not the same products as Wegovy, Ozempic, Zepbound or Mounjaro. Individual results vary.
Who should pick Semaglutide
Patients whose priorities include FDA-approved cardiovascular event reduction (SELECT), kidney protection in T2D+CKD (FLOW), or the broader outcome evidence base.
Who should pick Tirzepatide
Patients whose priority is a larger average weight-loss effect, or patients with moderate-to-severe OSA and obesity (Zepbound was the first drug FDA-approved for OSA).
Frequently asked
Is tirzepatide just stronger semaglutide?
No. Tirzepatide is a dual GIP/GLP-1 receptor agonist — different molecule, different mechanism. The added GIP component likely explains tirzepatide's larger weight effect.
Which is safer?
Both have similar safety profiles in trials, with gastrointestinal side effects most common. Choice should be based on indication, medical history and individual response, with a clinician.
Can you switch?
Yes, with clinical supervision. Patients sometimes switch based on tolerance or response.