Controlled study
SURMOUNT-1: weight change at 72 weeks
In SURMOUNT-1, mean weight changes at 72 weeks were −15.0%, −19.5% and −20.9% with tirzepatide 5, 10 and 15 mg, and −3.1% with placebo, under the treatment-regimen estimand.
The SURMOUNT-1 abstract reports adverse-event discontinuation in 4.3%, 7.1% and 6.2% of the 5, 10 and 15 mg groups, and 2.6% of the placebo group.
Weight results during 68 or 72 treatment weeks and a two-week sleep intervention answer different questions from a withdrawal comparison after initial treatment. SURMOUNT-4 provides that specific comparison for 52 weeks after randomization.
- Evidence design
- Randomized comparison
- Population
- Adults without diabetes with BMI >=30 kg/m2, or BMI >=27 kg/m2 with at least one weight-related complication.
- Assessment period
- Baseline to week 72; During the trial; precise safety window not verified
- Reported units
- % change; %
Keep in view
- These article results use the treatment-regimen estimand; current registry results include an analysis with a different discontinuation rule.
- Arm sizes were verified by group titles, not by array position in the registry.
See study details — SURMOUNT-1
Study design and methods
Randomized comparison
Randomized, double-blind, placebo-controlled trial; four parallel groups allocated 1:1:1:1; 72 weeks; phase 3.
Population
Adults without diabetes with BMI >=30 kg/m2, or BMI >=27 kg/m2 with at least one weight-related complication.
- Outcome definition
- Percent change in body weight from baseline
- Assessment period
- Value
- 72
- Unit
- weeks
- Reported statistic
- Mean
- Unit
- % change from baseline
- Randomized participants
- 2539
- Estimand and analysis rules
- Name
- treatment-regimen estimand
- Definition
- Effects regardless of treatment discontinuation in the intention-to-treat population, according to the primary article abstract.
- Registry analysis distinction
- The current registry primary-outcome results specify data excluding observations after prematurely stopping study drug and use outcome-specific analyzed denominators. They must not be relabeled as the publication treatment-regimen values. Here, arm sample sizes are randomized counts from the participant-flow module, mapped by explicit group titles.
Extracted outcomes
| Outcome and group | Reported value | Assessment period | Sample and denominators | Uncertainty |
|---|---|---|---|---|
| Percent change in body weight Tirzepatide 5 mg Effect estimate | -15 % change Mean Unit: % change | Baseline to week 72 Study weeks 0–72 | Reported N: 630 — intention-to-treat population
| 95% confidence interval: -15.9 to -14.2 |
| Percent change in body weight Tirzepatide 10 mg Effect estimate | -19.5 % change Mean Unit: % change | Baseline to week 72 Study weeks 0–72 | Reported N: 636 — intention-to-treat population
| 95% confidence interval: -20.4 to -18.5 |
| Percent change in body weight Tirzepatide 15 mg Effect estimate | -20.9 % change Mean Unit: % change | Baseline to week 72 Study weeks 0–72 | Reported N: 630 — intention-to-treat population
| 95% confidence interval: -21.8 to -19.9 |
| Percent change in body weight Placebo Effect estimate | -3.1 % change Mean Unit: % change | Baseline to week 72 Study weeks 0–72 | Reported N: 643 — intention-to-treat population
| 95% confidence interval: -4.3 to -1.9 |
| Discontinuation due to adverse events Tirzepatide 5 mg weekly Descriptive result; not an effect estimate | 4.3 % reported event percentage Unit: % | During the trial; precise safety window not verified | Reported N: Not reported or not verified — outcome-specific denominator not verified
| Confidence interval for this event was not verified; descriptive count or percentage. |
| Discontinuation due to adverse events Tirzepatide 10 mg weekly Descriptive result; not an effect estimate | 7.1 % reported event percentage Unit: % | During the trial; precise safety window not verified | Reported N: Not reported or not verified — outcome-specific denominator not verified
| Confidence interval for this event was not verified; descriptive count or percentage. |
| Discontinuation due to adverse events Tirzepatide 15 mg weekly Descriptive result; not an effect estimate | 6.2 % reported event percentage Unit: % | During the trial; precise safety window not verified | Reported N: Not reported or not verified — outcome-specific denominator not verified
| Confidence interval for this event was not verified; descriptive count or percentage. |
| Discontinuation due to adverse events Placebo Descriptive result; not an effect estimate | 2.6 % reported event percentage Unit: % | During the trial; precise safety window not verified | Reported N: Not reported or not verified — outcome-specific denominator not verified
| Confidence interval for this event was not verified; descriptive count or percentage. |
Percent change in body weight — Tirzepatide 5 mg: extraction context
- Outcome role
- Not specified in the consulted scope
- Scale reference
- baseline_body_weight
- Estimand and analysis rules
- Name
- treatment-regimen estimand
- Definition
- Effects regardless of treatment discontinuation in the intention-to-treat population, according to the primary article abstract.
- Extraction location
- Original article abstract; arm sample sizes cross-checked against registry participant flow
Percent change in body weight — Tirzepatide 10 mg: extraction context
- Outcome role
- Not specified in the consulted scope
- Scale reference
- baseline_body_weight
- Estimand and analysis rules
- Name
- treatment-regimen estimand
- Definition
- Effects regardless of treatment discontinuation in the intention-to-treat population, according to the primary article abstract.
- Extraction location
- Original article abstract; arm sample sizes cross-checked against registry participant flow
Percent change in body weight — Tirzepatide 15 mg: extraction context
- Outcome role
- Not specified in the consulted scope
- Scale reference
- baseline_body_weight
- Estimand and analysis rules
- Name
- treatment-regimen estimand
- Definition
- Effects regardless of treatment discontinuation in the intention-to-treat population, according to the primary article abstract.
- Extraction location
- Original article abstract; arm sample sizes cross-checked against registry participant flow
Percent change in body weight — Placebo: extraction context
- Outcome role
- Not specified in the consulted scope
- Scale reference
- baseline_body_weight
- Estimand and analysis rules
- Name
- treatment-regimen estimand
- Definition
- Effects regardless of treatment discontinuation in the intention-to-treat population, according to the primary article abstract.
- Extraction location
- Original article abstract; arm sample sizes cross-checked against registry participant flow
Discontinuation due to adverse events — Tirzepatide 5 mg weekly: extraction context
- Outcome role
- Descriptive safety outcome
- Extraction location
- Original article abstract, safety results
- The safety denominator was not inferred from the randomized arm size.
Discontinuation due to adverse events — Tirzepatide 10 mg weekly: extraction context
- Outcome role
- Descriptive safety outcome
- Extraction location
- Original article abstract, safety results
- The safety denominator was not inferred from the randomized arm size.
Discontinuation due to adverse events — Tirzepatide 15 mg weekly: extraction context
- Outcome role
- Descriptive safety outcome
- Extraction location
- Original article abstract, safety results
- The safety denominator was not inferred from the randomized arm size.
Discontinuation due to adverse events — Placebo: extraction context
- Outcome role
- Descriptive safety outcome
- Extraction location
- Original article abstract, safety results
- The safety denominator was not inferred from the randomized arm size.
What the curated evidence supports
- In SURMOUNT-1, mean weight changes at 72 weeks were −15.0%, −19.5% and −20.9% with tirzepatide 5, 10 and 15 mg, and −3.1% with placebo, under the treatment-regimen estimand.
- The SURMOUNT-1 abstract reports adverse-event discontinuation in 4.3%, 7.1% and 6.2% of the 5, 10 and 15 mg groups, and 2.6% of the placebo group.
- Weight results during 68 or 72 treatment weeks and a two-week sleep intervention answer different questions from a withdrawal comparison after initial treatment. SURMOUNT-4 provides that specific comparison for 52 weeks after randomization.
Limitations
- These article results use the treatment-regimen estimand; current registry results include an analysis with a different discontinuation rule.
- Arm sizes were verified by group titles, not by array position in the registry.
Verification scope
Verified through 2026-11-04 within the consulted scope.
- Bibliographic metadata checked
- Yes
- Original article abstract consulted
- Yes
- Full-text consultation
- Not consulted
- Official trial registry consulted
- Yes
- Statistical analysis plan consulted
- No
- Verification boundary
- Verification is limited to the specific fields and sources consulted; it is not a full systematic appraisal or GRADE rating.
Source record
Tirzepatide Once Weekly for the Treatment of Obesity (2022). The New England journal of medicine.