GLP-1 Evidence

Not medical advice. A record of published research and our assessments of it. The limits

Continued Treatment With Tirzepatide for Maintenance of Weight Reduction in Adults With Obesity: The SURMOUNT-4 Randomized Clinical Trial

Design
Randomized trial · 670 participants · Intermediate outcome
Match to healthy normal-weight adults aged 55–75
Different populationObesity without diabetes; younger.
Could weight loss explain it?
Not applicable[Auto] Participants had obesity and/or type 2 diabetes and the abstract does not separate direct drug effects from weight loss or glycaemic improvement.
Study tier
Study tier 1[Auto] Randomized trial of moderate size; outcome type and follow-up limit certainty (auto-provisional).
Assessment
Version 2 · curated · Sep 13, 2026

Study facts come from the paper. Population match, weight-loss explanation and study tier are our judgments, made against the reference group of healthy normal-weight adults aged 55–75.

People who switched from tirzepatide to placebo after 36 weeks regained about 14% of body weight within a year, while those continuing lost a further 5.5%. Stopping reverses the effect.

01Findings

What the study reported

Drugs
Tirzepatide
Dose
10 or 15 mg weekly
Route
subcutaneous
Treatment duration
36-week lead-in then 52-week randomized withdrawal
Comparator
placebo
Primary outcome
Percent weight change from week 36 to 88
Effect
-5.5% (continued) vs +14.0% (placebo); difference -19.4%
95% confidence interval
-21.2 to -17.7
P value
<0.001
Follow-up
88 weeks
Adverse events
Not extracted
Limitations
Auto-classified from abstract only; effect estimates, adverse events and limitations not extracted. Requires manual review.

Who was studied

Mean age
48
Sex distribution
71% female
Obesity status
obesity or overweight with complication
Diabetes status
excluded
Sample size
670

Study quality details

Study design
Randomized controlled trial
Sample size
670
Randomization
yes
Blinding
double-blind
Comparator
placebo
Follow up duration
36 weeks
Outcome type
unknown
Replication
not assessed (auto)
Consistency with other evidence
not assessed (auto)
Population applicability
INDIRECT
Statistical precision
CI reported: 95% CI, -21
Risk of bias
not assessed (auto)
Funding conflicts
no
Peer review status
yes
02Funding

Funding and conflicts

Funding
Eli Lilly
Industry funded
Yes
Manufacturer
Eli Lilly
Sponsor role
Sponsor designed and analysed.
Author conflicts
Authors report Eli Lilly relationships; sponsor co-authors.
Independent replication
consistent with STEP 1 extension

Funding is shown on every study and never used to score it.

03Claims

Claims this study bears on

04Source

The source, as retrieved

Abstract

[IMPORTANCE] The effect of continued treatment with tirzepatide on maintaining initial weight reduction is unknown. [OBJECTIVE] To assess the effect of tirzepatide, with diet and physical activity, on the maintenance of weight reduction. [DESIGN, SETTING, AND PARTICIPANTS] This phase 3, randomized withdrawal clinical trial conducted at 70 sites in 4 countries with a 36-week, open-label tirzepatide lead-in period followed by a 52-week, double-blind, placebo-controlled period included adults with a body mass index greater than or equal to 30 or greater than or equal to 27 and a weight-related complication, excluding diabetes. [INTERVENTIONS] Participants (n = 783) enrolled in an open-label lead-in period received once-weekly subcutaneous maximum tolerated dose (10 or 15 mg) of tirzepatide for 36 weeks. At week 36, a total of 670 participants were randomized (1:1) to continue receiving tirzepatide (n = 335) or switch to placebo (n = 335) for 52 weeks. [MAIN OUTCOMES AND MEASURES] The primary end point was the mean percent change in weight from week 36 (randomization) to week 88. Key secondary end points included the proportion of participants at week 88 who maintained at least 80% of the weight loss during the lead-in period. [RESULTS] Participants (n = 670; mean age, 48 years; 473 [71%] women; mean weight, 107.3 kg) who completed the 36-week lead-in period experienced a mean weight reduction of 20.9%. The mean percent weight change from week 36 to week 88 was -5.5% with tirzepatide vs 14.0% with placebo (difference, -19.4% [95% CI, -21.2% to -17.7%]; P < .001). Overall, 300 participants (89.5%) receiving tirzepatide at 88 weeks maintained at least 80% of the weight loss during the lead-in period compared with 16.6% receiving placebo (P < .001). The overall mean weight reduction from week 0 to 88 was 25.3% for tirzepatide and 9.9% for placebo. The most common adverse events were mostly mild to moderate gastrointestinal events, which occurred more commonly with tirzepatide vs placebo. [CONCLUSIONS AND RELEVANCE] In participants with obesity or overweight, withdrawing tirzepatide led to substantial regain of lost weight, whereas continued treatment maintained and augmented initial weight reduction. [TRIAL REGISTRATION] ClinicalTrials.gov Identifier: NCT04660643.

Where this record came from

SourceRetrievedIdentifier
pubmedSep 13, 202638078870
first ingestion