Ozempic / Wegovy vs Mounjaro / Zepbound. The head-to-head trial, the dosing, and the side-effect tradeoff.
| Semaglutide | Tirzepatide | |
|---|---|---|
| Receptors | GLP-1 | GLP-1 + GIP |
| Brand names | Ozempic, Wegovy, Rybelsus | Mounjaro, Zepbound |
| Weight loss (68-72 wk) | ~15-18% | ~22% |
| Max dose | 2.4 mg / week | 15 mg / week |
| Starting dose | 0.25 mg / week | 2.5 mg / week |
| Titration | 4 weeks per step | 4 weeks per step |
| Half-life | ~7 days | ~5 days |
| Nausea (most common SE) | ~44% at peak dose | ~33% at peak dose |
| Status | FDA approved | FDA approved |
| Cost / mo (US, cash) | ~$1,000-1,350 | ~$1,000-1,350 |
SURMOUNT-5 was the direct head-to-head: 751 adults with obesity (no diabetes), 72 weeks of either semaglutide 2.4 mg or tirzepatide max-tolerated. Tirzepatide produced ~20.2% mean weight loss vs ~13.7% on semaglutide — about a 6.5 percentage-point spread, statistically significant.
Tirzepatide activates both GLP-1 and GIP receptors. GIP appears to amplify GLP-1's appetite-suppressing effect while also reducing nausea — patients tolerate higher effective doses, which translates to more weight loss.
You want the most mature safety record (semaglutide has been in market since 2017). Your insurance covers Wegovy but not Zepbound. You've had a poor response to GIP-agonism in the past. You want oral (Rybelsus is the only oral GLP-1 currently available).
Maximum weight-loss efficacy is the primary goal. You've plateaued on semaglutide. You tolerate the slightly faster titration curve. Your insurance covers Mounjaro or Zepbound.
Epti lets you log your protocol — every dose, side-effect, and outcome on one timeline. The only way to know which works for you.