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 momentum is now with Lilly. Visible Alpha, a data firm, expects its sales of obesity drugs to overtake Novo’s by 2027 (see chart 2). Lilly’s edge rests on a more effective drug, better execution, keener pricing and a stronger pipeline.

Investors are worried Novo Nordisk's competition with Eli Lilly is heating up and that the first-to-market GLP-1 leader is losing ground.