Eli Lilly's popular obesity injection Zepbound trounces Novo Nordisk's Wegovy when it comes to shedding weight, according to new research published Monday, intensifying competition between the two pharma giants as they compete for the lucrative drug market and dig in to defend their dominant positions against an array of hopeful rivals rushing to market.

Obese and overweight adults taking tirzepatide (the generic name for Zepbound and Mounjaro) lost more weight and lost it faster than adults taking semaglutide (the generic name for Wegovy and Ozempic) according to new peer reviewed research published in JAMA Internal Medicine.

While most...