Semaglutide vs Tirzepatide
This page has not yet been reviewed by a credentialed medical professional. It is educational and is not medical advice.
Short answer: In the one head-to-head obesity trial, tirzepatide produced more average weight loss (-20.2% vs -13.7% at 72 weeks). Both are FDA-approved with large trials behind them.
| Semaglutide FDA-approved | Tirzepatide FDA-approved | |
|---|---|---|
| Mechanism | GLP-1 receptor agonist | Dual GIP and GLP-1 receptor agonist |
| Evidence grade | FDA-approved | FDA-approved |
| Brand names | Ozempic, Wegovy, Rybelsus | Mounjaro, Zepbound |
| Weight loss, placebo-controlled trial | -14.9% at 68 weeks (STEP 1) | -15.0% to -20.9% at 72 weeks (SURMOUNT-1) |
| Cardiovascular outcome data | Reduced major events in SUSTAIN-6 (type 2 diabetes) | Compared with dulaglutide in a cardiovascular outcomes trial |
| Common side effects | Nausea, vomiting, diarrhea, constipation | Same gastrointestinal pattern |
| WADA | Not prohibited | Not prohibited |
Takeaway
Cross-trial comparisons are unreliable because the populations differ. The direct trials (SURPASS-2 in type 2 diabetes and SURMOUNT-5 in obesity) both favoured tirzepatide, but both were open-label and funded by the maker of tirzepatide.
FAQ
Is tirzepatide stronger than semaglutide?
On average for weight loss, yes in head-to-head trials, but individual response varies, and tolerability and cost matter too.