Semaglutide vs Tirzepatide
Two weekly GLP-1 medicines, one head-to-head trial. Here is how they differ, what each costs self-pay, and what to ask your prescriber.
The short answer
Tirzepatide produced more average weight loss than semaglutide in the one head-to-head trial, 20.2% against 13.7% of body weight over 72 weeks. That trial was open-label and funded by the maker of tirzepatide, and averages do not predict your result.
The practical choice usually comes down to how well you tolerate each drug, what your plan covers and what you can pay. A prescriber who has your history should make the call.
Side by side
| Semaglutide | Tirzepatide | |
|---|---|---|
| Active ingredient | Semaglutide | Tirzepatide |
| Brand names | Wegovy (weight management), Ozempic (type 2 diabetes) | Zepbound (weight management), Mounjaro (type 2 diabetes) |
| How it works | GLP-1 receptor agonist | GIP and GLP-1 receptor agonist |
| Dosing | Weekly injection | Weekly injection |
| Head-to-head weight loss (SURMOUNT-5, 72 weeks) | 13.7% average | 20.2% average |
| Manufacturer self-pay (reviewed Nov 3, 2026) | Wegovy injection $349/mo; $199 intro for eligible new patients through 12/31/2026 | Zepbound vials from $299/mo (2.5 mg), $399 (5 mg), $449 higher doses with refill terms |
Prices reviewed November 3, 2026. Programs change often, so confirm on the manufacturer pages. We re-check these after December 31, 2026.
Questions to ask your prescriber
- Which of these fits my health history and goals?
- What is the full monthly cost for the dose I would start on, and for the dose I may reach?
- Does my plan cover it, and what does prior authorization need?
- What side effects should make me call you?
- If I stop, what happens to my weight and my next steps?
Find providers by area: semaglutide near me or tirzepatide near me.
Frequently asked questions
Which works better, semaglutide or tirzepatide?
On average weight loss, tirzepatide did better in the one head-to-head trial. In SURMOUNT-5 (NEJM, 2025), adults with obesity taking tirzepatide (Zepbound) lost an average of 20.2% of body weight over 72 weeks, compared with 13.7% on semaglutide (Wegovy). The trial was open-label and sponsored by Eli Lilly. Averages hide wide individual differences, so tolerance, cost and coverage often decide the choice.
What is the difference between semaglutide and tirzepatide?
Semaglutide activates the GLP-1 receptor. Tirzepatide activates both the GIP and GLP-1 receptors. Both are once-weekly injections that reduce appetite and slow stomach emptying. Semaglutide is sold as Wegovy (weight management) and Ozempic (type 2 diabetes). Tirzepatide is sold as Zepbound (weight management) and Mounjaro (type 2 diabetes).
Which is cheaper?
Self-pay prices changed in 2026 and differ by dose. When we reviewed the manufacturer pages on November 3, 2026, NovoCare listed Wegovy injection at $349 a month, with a $199 introductory price for eligible new patients through December 31, 2026. LillyDirect listed Zepbound vials at $299 for 2.5 mg, $399 for 5 mg and $449 for higher doses when refill terms are met. Check both pages for current terms before you compare.
Do they have the same side effects?
They share the same main ones. Nausea, diarrhea, vomiting, constipation and stomach pain are the most common, and they are usually worst when starting or raising a dose. Both carry a boxed warning about thyroid C-cell tumors. Your prescriber will go over who should not take them, including people with certain thyroid cancer histories or a personal or family history of MEN 2.
Can I switch from one to the other?
Prescribers do switch patients, but the doses are not interchangeable and the right starting dose after a switch is a medical decision. Do not change drugs or doses on your own. Ask your prescriber how to switch and what to expect.
Does insurance cover both?
Coverage varies by plan, and plans often cover these drugs for diabetes more readily than for weight management. See our guide on whether insurance covers Zepbound and Wegovy, and call your plan to ask about prior authorization and quantity limits.