The short answer
Tirzepatide produced substantially greater average weight loss than placebo over 72 weeks in adults without diabetes. Results differed by study dose.
What was compared?
The trial randomly assigned 2,539 adults with obesity, or overweight plus a related complication, to weekly tirzepatide or placebo. Participants and investigators were blinded to the assignment.
Average weight change was −15.0% with 5 mg, −19.5% with 10 mg, −20.9% with 15 mg, and −3.1% with placebo. These were study regimens; the comparison included participants regardless of treatment discontinuation.
Percent of starting weight
Original chart based on the study. Values are reported group averages.
| Group or measure | Average result |
|---|---|
| Tirzepatide 5 mg | −15.0% |
| Tirzepatide 10 mg | −19.5% |
| Tirzepatide 15 mg | −20.9% |
| Placebo | −3.1% |
The other side of the result
Digestive adverse events were most common, usually mild or moderate and occurring during dose increases. Adverse events led 4.3%, 7.1%, and 6.2% of participants in the respective tirzepatide groups to stop treatment, compared with 2.6% with placebo.
The trial establishes average effects against placebo. It does not compare tirzepatide with another active medicine or predict one person's outcome.
Sources
SURMOUNT-1, NEJM, 2022. Funded by Eli Lilly. Study abstract · Paper.