The takeaway
In SURPASS-SWITCH, people switching to tirzepatide lost more weight than people increasing dulaglutide. Participants had inadequately controlled type 2 diabetes.
The study
The open-label trial assigned 282 adults to switch or increase treatment for 40 weeks. Average losses were 10.5 kg versus 3.6 kg, including treatment changes and discontinuation.
282 adults randomized; includes treatment changes and discontinuation
Original visual based on the study.
| Group or measure | Result |
|---|---|
| Switch to tirzepatide | 10.5 kg |
| Increase dulaglutide | 3.6 kg |
The trade-offs
Nausea occurred in 25.2% versus 18.9%; diarrhea in 22.3% versus 13.3%. Four tirzepatide participants and one dulaglutide participant stopped treatment because of adverse events. Ten participants in each group reported serious adverse events.
What this means for you
A later analysis found weight-loss differences pointed in the same direction across subgroups. Some groups were small; safety differences were not established. Results may not apply without diabetes.
Eli Lilly funded the trial.
Sources
Violante-Ortiz and colleagues, BMJ Open Diabetes Research & Care, 2026