Tirzepatide vs. Semaglutide for Patients with Obesity: A Head-to-Head Trial

In previous studies of tirzepatide alone or semaglutide alone, weight reduction was somewhat greater with tirzepatide than with semaglutide. Now, to corroborate those findings, the manufacturer of tirzepatide has conducted a head-to-head, randomized, open-label comparison of the two drugs: 751 people with obesity (mean body-mass index, 39 kg/m²), but without diabetes received weekly injections of either tirzepatide or semaglutide, each titrated to maximal recommended doses if tolerated.

At 72 weeks, the mean percentage decrease in weight was significantly greater with tirzepatide than with semaglutide (20% vs. 14%). Gastrointestinal side effects occurred frequently in both groups but led to discontinuation of treatment in only 3% and 6% of p…