The short answer
A large health-record study found greater weight loss among people receiving tirzepatide than semaglutide. Its design matters: researchers observed care rather than randomly assigning medicines.
Who was included?
The 2024 analysis matched 18,386 US adults with overweight or obesity. About half had type 2 diabetes. It studied formulations labeled for diabetes, not a direct comparison of the obesity-branded versions.
Percent of starting weight
Original chart based on the study. Values are reported group results.
| Group or measure | Result |
|---|---|
| Tirzepatide | −15.3% |
| Semaglutide | −8.3% |
What did the records show?
Among people still receiving treatment, average weight change at 12 months was −15.3% with tirzepatide versus −8.3% with semaglutide.
Discontinuation ended follow-up for more than half in each group. The headline numbers therefore do not describe everyone who started treatment. Recorded gastrointestinal adverse-event risks did not differ significantly, but routine records can miss side effects.
How should we read it?
Matching made the groups more comparable, but cannot remove every difference in motivation, care or dosing. This is evidence of an association, not the same certainty as random assignment.
For the later randomized comparison, see SURMOUNT-5.
Sources
Rodriguez and colleagues, JAMA Internal Medicine, 2024. Read the paper.