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.

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.

Nearly 32% of Zepbound users lost at least a quarter of their body weight, compared with about 16% of Wegovy users. In both groups, weight loss was about 6% lower in men than in women, AP said. Both groups saw health improvements in blood pressure, blood sugar and blood fat levels, too.