The obesity drug helped patients reduce their waist size by an extra two inches compared to those on Novo Nordisk’s Wegovy in a head-to-head study of the two drugs.

Eli Lilly said on Sunday its drug Zepbound was superior to Novo Nordisk's Wegovy across five weight-loss targets such as reducing waist circumference, citing data from a head-to-head trial. The data is the first head-to-head trial comparing the wildly popular medicines,

Participants who took tirzepatide — which is sold as Zepbound by Eli Lilly — lost an average of 50 pounds over 72 weeks. Those who took semaglutide — known as Novo Nordisk's Wegovy, lost about 33 pounds.