INDIANAPOLIS, May 12, 2025 – Eli Lilly announced on Sunday that its weight-loss drug, Zepbound, outperformed Novo Nordisk’s Wegovy in a head-to-head trial, showing superior results across five key weight-loss targets, including waist circumference reduction.

The trial, the first of its kind to directly compare the two drugs, revealed that Zepbound helped nearly 25% more participants lose more than 15% of their body weight compared to Wegovy. Zepbound also achieved a superior average waist circumference reduction of 18.4 cm, compared to 13 cm for Wegovy, according to Lilly.

This data bolsters Lilly's push to secure broader insurance coverage and gain a larger share of the obesity drug market, which is expected to exceed $150 billion annually by the end of the decade. Zepbound’s performance could further position it as a stronger contender against Wegovy, the leading drug in the market.

Novo Nordisk, however, noted in a statement on Monday that the weight loss achieved by Wegovy in the recent trial was lower than in a similar 2021 trial with a comparable dose. The company also pointed out that Wegovy remains the only GLP-1 agonist approved to prevent major cardiovascular events, including heart attacks.

While Lilly’s Zepbound mimics two gut hormones to aid weight loss, Novo’s Wegovy relies on a single mode of action. In previous trials, Zepbound led to more than 22% weight loss after 72 weeks, while Wegovy produced a 15% weight reduction after 68 weeks.

The announcement follows news that CVS Health, which recently made adjustments to its list of reimbursed drugs, dropped Zepbound from some of its coverage lists, instead opting to favor Wegovy.

As both companies continue to compete for dominance in the fast-growing obesity treatment market, the results of this head-to-head trial highlight the ongoing battle for consumer and insurance support.