High-dose Wegovy produces 18.7% weight loss but trails Zepbound's 20.9%

A 7.2-milligram dose of Wegovy (semaglutide) led people with obesity to lose an average of 18.7% of their body weight over 72 weeks in a clinical trial, Novo Nordisk said Jan. 17 ^[1]. That is a large weight loss on its own, but it came in below the 20.9% average that tirzepatide, the drug in Eli Lilly's Zepbound, produced over 72 weeks in its own pivotal trial ^[1].

The trial numbers

The 72-week study tested three groups. People taking the 7.2-milligram dose lost 18.7% of their weight, people taking the currently approved 2.4-milligram dose lost 15.6%, and people taking a placebo lost 3.9%, Novo said ^[1]. The company counted all participants in these figures, regardless of how closely they followed the treatment schedule ^[1].

Zepbound's 20.9% figure also covers 72 weeks, or about 17 months, of treatment ^[1]. The two numbers come from separate studies, not from one trial that tested the two drugs against each other ^[1].

STAT reported that Novo Nordisk has faced pressure from investors to develop drugs that can deliver greater weight loss than those made by Eli Lilly, and the company released the high-dose results on Friday, Jan. 17 ^[1].

Why it matters for patients

The strength tested in this study is not the strength sold today. The approved Wegovy dose is 2.4 milligrams, and the 18.7% result applies to the experimental 7.2-milligram dose ^[1]. So this announcement does not change what is currently available at the pharmacy, and the higher dose is not something patients can get on the basis of these results.

Average weight loss figures describe groups, not individuals. The 18.7% and 15.6% totals do not show how widely results varied from person to person within the trial, and Novo has not reported that range ^[1].

The comparison with Zepbound is not a head-to-head result. Because each figure comes from a different trial run by a different company, they do not show how the two drugs would compare if tested side by side in the same patients ^[1]. People deciding between the two medicines still lack that direct comparison.

Several details that would matter to patients have not been disclosed. Novo has not reported how many participants stopped treatment, how common side effects were at 7.2 milligrams, or whether the gap between 18.7% and 15.6% was statistically significant. It also has not said whether it plans to seek FDA approval for the 7.2-milligram dose, or when that decision might come. The cost of a higher dose, and whether insurers would cover it, have not been reported either.