Injectable division

Semaglutide 2.4 mg (Wegovy)

BCompetitive

Novo Nordisk · approved

Injectable division

Tirzepatide (Zepbound)

Class-leadingA

Eli Lilly · approved

12%

Efficacy

leads · 18%

Mild (+3.9)

Tolerability

Mild (+3.6)

Subcutaneous injection

Route

Subcutaneous injection

None

Food / water rule

None

Refrigerated (room temperature up to 28 days)

Storage

Refrigerated (room temperature up to 21 days)

The call: The board favors tirzepatide: it is class-leading where semaglutide 2.4 mg is competitive, and it is at least as easy to stay on. The displayed 18% and 12% scores are standardized cross-trial values from SURMOUNT-1 and STEP 1. Separately, the randomized SURMOUNT-5 direct comparison independently supports tirzepatide's advantage for the tirzepatide 10/15 mg and semaglutide 1.7/2.4 mg regimens tested there. Tirzepatide, clearly, on the evidence.

Where the displayed 12% and 18% come from

They are cross-trial board values: semaglutide's 12% is the placebo-adjusted treatment-policy result from STEP 1 at 2.4 mg, while tirzepatide's 18% is the placebo-adjusted treatment-regimen result from SURMOUNT-1 at 15 mg. They are not SURMOUNT-5 figures. SURMOUNT-5 separately randomized maximum-tolerated tirzepatide 10/15 mg against semaglutide 1.7/2.4 mg and found 20.2% versus 13.7% mean weight loss at 72 weeks. Those are absolute results from the direct trial, which independently supports tirzepatide's advantage for the regimens tested there.

Sources: STEP 1 · SURMOUNT-1 · SURMOUNT-5

What about Wegovy HD?

STEP UP showed that semaglutide 7.2 mg outperformed 2.4 mg: 18.7% versus 15.6% average weight loss on the treatment-policy estimand, a 3.1-percentage-point active-arm difference. But 7.2 mg has not been tested directly against tirzepatide. STEP UP is not a head-to-head Zepbound comparison, and this conditional higher dose is shown without a separate board rank.

Sources: STEP UP · FDA Wegovy label

Standalone, this page carries its own key: Efficacy = % body weight lost vs placebo, using the treatment-policy or treatment-regimen estimate. Tolerability = AE-discontinuation over placebo (Mild 1 to 5 · Notable 5 to 10 · Heavy over 10 points). Winners are called only across a tier or band boundary; within one, the drugs are effectively tied. The side marked leads or gentler wins that axis.

Semaglutide 2.4 mg verdict · Tirzepatide verdict · How this is scored