The one comparison in this class settled by an actual head-to-head trial. SURMOUNT-5 put them in the same ring, same patients, same clock.
Semaglutide proved the GLP-1 class at scale: 14.9% in STEP-1, tens of thousands of patients, full approval. Tirzepatide added GIP to the mechanism and beat it head to head: 20.2% vs 13.7% in SURMOUNT-5, the only direct incretin showdown ever run. Semaglutide is the benchmark; tirzepatide is the efficacy leader. Both facts can be true.
| Semaglutide | Tirzepatide | |
|---|---|---|
| Mechanism | GLP-1 receptor agonist | GIP + GLP-1 dual agonist |
| Head-to-head | SURMOUNT-5: tirzepatide 20.2% vs semaglutide 13.7% at 72 weeks | |
| Landmark trial | STEP-1: 14.9% at 68 weeks | SURMOUNT-1: 20.9% at 72 weeks |
| Status | FDA-APPROVED | FDA-APPROVED |
| Safety database | Largest in the class | Large (SURMOUNT program) |
| TrueNorth from | C$35 (10 mg) | C$53 (30 mg) |
| View Semaglutide | View Tirzepatide | |
Most compound comparisons are cross-trial guesswork. SURMOUNT-5 is the exception: randomized, same population, same duration. Tirzepatide won by about 6.5 percentage points with a comparable GI tolerability profile. That result is why every investigational compound behind them gets measured against tirzepatide, not semaglutide.
But "beat" is not "replaced." Semaglutide's safety database is unmatched, its supply chain is mature, and for research programs that need the reference standard, it remains the right call. Efficacy is one axis; evidence maturity is another.
Yes, SURMOUNT-5 compared tirzepatide directly against semaglutide in adults with obesity: tirzepatide 15 mg achieved 20.2% mean weight loss at 72 weeks versus 13.7% for semaglutide 2.4 mg. This is one of the only true head-to-head trials in the incretin class.
Tirzepatide engages two receptors (GIP + GLP-1) while semaglutide engages one (GLP-1). The dual mechanism produced roughly 6.5 percentage points more weight loss in SURMOUNT-5, with a similar GI side-effect profile.
Absolutely. It has the largest safety database of any incretin, full regulatory approval, and remains the benchmark every new compound is measured against. For many research programs it is the right reference compound.
Market pricing generally favors semaglutide per milligram, but cost-per-program depends on dose and duration. TrueNorth lists both in CAD with volume discounts; check the product pages for current pricing.
All compounds are sold strictly as laboratory research chemicals, not for human consumption. Trial figures are mean changes in the cited trial populations.
