Semaglutide versus placebo in individuals with poor weight loss after bariatric surgery: a double-blinded, randomized, placebo-controlled trial.

Stanley C, Mallik R, Hamid N, Jassil FC, Reuven V, Ruwona T, Dicken SJ, Qamar S, Norton B, Kingett H, Pucci A, Magee C and 11 more

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Boniface D, Batterham RL, Devalia K, Mok J, Elkalaawy M, Loy J, Jenkinson A, Markakis H, Adamo M, Brown A, Makaronidis J

Nature medicine22 May 2026Cited by 1 (Europe PMC)

PMID42174253PMCIDPMC13375533DOI10.1038/s41591-026-04416-4PepBankPUB-42174253

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Summary

A suboptimal clinical response after metabolic and bariatric surgery (MBS) is common and carries considerable health concerns. Here a double-blinded, randomized (1:1), placebo-controlled trial using semaglutide 2.4 mg weekly (BARI-STEP) recruited adult participants at least 1 year after gastric bypass or sleeve gastrectomy with a suboptimal clinical response, defined as less than 20% weight loss from surgery. This was an adjunct to lifestyle intervention with a 500-kcal daily energy deficit. The primary outcome was percentage weight loss after 68-week treatment on an intention-to-treat analysis. Seventy participants (mean (s.d.) age = 47.3 (10.3) years, 58 (82.9%) female and 12 (17.1%) male) were randomized to receive 2.4 mg semaglutide (n = 35) or placebo (n = 35). The intention-to-treat sample included 63 participants. Estimated change in mean (s.d.) percentage weight loss from baseline to week 68 was -18.0 (9.2) with semaglutide 2.4 mg (n = 34) versus +0.4 (7.0) with placebo (n = 29). The mean adjusted treatment difference in percentage body weight change for semaglutide 2.4 mg versus placebo was -19.18 (95% confidence interval -23.4 to -14.8; P < 0.001). Adverse events (AEs) were consistent with the known safety and tolerability profile of semaglutide, with no new safety concerns for the post-bariatric population. There were eight serious AEs, one suspected unexpected serious adverse reaction and no treatment-related deaths. BARI-STEP demonstrates that in people with a suboptimal clinical response after MBS, semaglutide results in substantial and clinically significant body weight reduction along with improvement in metabolic parameters and quality of life, compared to placebo. These findings suggest that semaglutide 2.4 mg is a safe and effective treatment option for this patient population. ClinicalTrials.gov: NCT05073835 .

CC BYText from Europe PMC. Highlighted sentences are the source of results.

Results from this study4

4 results from studies that gave the peptide. 4 results from people.

01HumanRandomized controlled trialEfficacy outcome
In adults with poor weight loss after bariatric surgery, semaglutide 2.4 mg changed body weight by -18.0% at week 68 versus +0.4% with placebo.
In plain wordsIn adults with poor weight loss after bariatric surgery, semaglutide 2.4 mg led to weight loss while placebo did not.
Peptide
Semaglutide
Outcome
DecreasePercentage weight change from baseline to week 68
Study
n = 63
Comparator
Placebo
Analysis
Primary
Outcome group
Body weight · Metabolic and weight
Studied dose
2.4 mg weekly · 68 weeksAs given in this study (human).
Measurements
Percentage weight change
−18%
semaglutide 2.4 mg
Percentage weight change
0.4%
placebo
Source sentences
Summary
Estimated change in mean (s.d.) percentage weight loss from baseline to week 68 was -18.0 (9.2) with semaglutide 2.4 mg (n = 34) versus +0.4 (7.0) with placebo (n = 29).
2 context sentences(design, population, supporting numbers)
Summary · context
Here a double-blinded, randomized (1:1), placebo-controlled trial using semaglutide 2.4 mg weekly (BARI-STEP) recruited adult participants at least 1 year after gastric bypass or sleeve gastrectomy with a suboptimal clinical response, defined as less than 20% weight loss from surgery.
Summary · context
Seventy participants (mean (s.d.) age = 47.3 (10.3) years, 58 (82.9%) female and 12 (17.1%) male) were randomized to receive 2.4 mg semaglutide (n = 35) or placebo (n = 35).
Show in the study text Report a problemFND-4217425301
02HumanRandomized controlled trialEfficacy outcome
In adults with poor weight loss after bariatric surgery, the adjusted treatment difference in percentage body weight change for semaglutide 2.4 mg versus placebo was -19.18.
In plain wordsIn adults with poor weight loss after bariatric surgery, semaglutide 2.4 mg lowered body weight far more than placebo.
Peptide
Semaglutide
Outcome
DecreaseAdjusted treatment difference in body weight change
Study
n = 63
Comparator
Placebo
Analysis
Primary
Outcome group
Body weight · Metabolic and weight
Studied dose
2.4 mg weekly · 68 weeksAs given in this study (human).
Measurements
Adjusted treatment difference
−19.18%
vs placebo
Source sentences
Summary
The mean adjusted treatment difference in percentage body weight change for semaglutide 2.4 mg versus placebo was -19.18 (95% confidence interval -23.4 to -14.8; P < 0.001).
2 context sentences(design, population, supporting numbers)
Summary · context
Here a double-blinded, randomized (1:1), placebo-controlled trial using semaglutide 2.4 mg weekly (BARI-STEP) recruited adult participants at least 1 year after gastric bypass or sleeve gastrectomy with a suboptimal clinical response, defined as less than 20% weight loss from surgery.
Summary · context
Seventy participants (mean (s.d.) age = 47.3 (10.3) years, 58 (82.9%) female and 12 (17.1%) male) were randomized to receive 2.4 mg semaglutide (n = 35) or placebo (n = 35).
Show in the study text Report a problemFND-4217425302
03HumanRandomized controlled trialSafety outcome
In adults with poor weight loss after bariatric surgery, adverse events with semaglutide matched its known profile, with no new safety concerns.
In plain wordsIn adults with poor weight loss after bariatric surgery, semaglutide side effects matched what is already known, and no new safety concerns appeared.
Peptide
Semaglutide
Outcome
Direction not reportedAdverse events profile
Study
n = 70
Outcome group
Adverse events · Whole body
Studied dose
2.4 mg weekly · 68 weeksAs given in this study (human).
Source sentences
Summary
Adverse events (AEs) were consistent with the known safety and tolerability profile of semaglutide, with no new safety concerns for the post-bariatric population.
2 context sentences(design, population, supporting numbers)
Summary · context
Here a double-blinded, randomized (1:1), placebo-controlled trial using semaglutide 2.4 mg weekly (BARI-STEP) recruited adult participants at least 1 year after gastric bypass or sleeve gastrectomy with a suboptimal clinical response, defined as less than 20% weight loss from surgery.
Summary · context
Seventy participants (mean (s.d.) age = 47.3 (10.3) years, 58 (82.9%) female and 12 (17.1%) male) were randomized to receive 2.4 mg semaglutide (n = 35) or placebo (n = 35).
Show in the study text Report a problemFND-4217425303
04HumanRandomized controlled trialSafety outcome
In adults with poor weight loss after bariatric surgery, the trial recorded eight serious adverse events, one suspected unexpected serious adverse reaction and no treatment-related deaths.
In plain wordsIn adults with poor weight loss after bariatric surgery, the trial recorded eight serious adverse events and no treatment-related deaths.
Peptide
Semaglutide
Outcome
Not applicableSerious adverse events and deaths
Study
n = 70
Outcome group
Adverse events · Whole body
Studied dose
2.4 mg weekly · 68 weeksAs given in this study (human).
Source sentences
Summary
There were eight serious AEs, one suspected unexpected serious adverse reaction and no treatment-related deaths.
2 context sentences(design, population, supporting numbers)
Summary · context
Here a double-blinded, randomized (1:1), placebo-controlled trial using semaglutide 2.4 mg weekly (BARI-STEP) recruited adult participants at least 1 year after gastric bypass or sleeve gastrectomy with a suboptimal clinical response, defined as less than 20% weight loss from surgery.
Summary · context
Seventy participants (mean (s.d.) age = 47.3 (10.3) years, 58 (82.9%) female and 12 (17.1%) male) were randomized to receive 2.4 mg semaglutide (n = 35) or placebo (n = 35).
Show in the study text Report a problemFND-4217425304

AI wrote and checked these results. AI can make mistakes, so check important results against the source.

Registered trials1

Trials this study reports on, or that list this study as a reference. Registry data from ClinicalTrials.gov.

1 trial · 1 ongoing · source ClinicalTrials.gov (opens in a new tab)

Active, not recruitingPhase 3NCT05073835

Semaglutide 2.4 mg in Patients With Poor Weight-loss

University College, Londonn = 701 Nov 2022 to est. Sept 2025

Obesity · Diabetes · Metabolic Syndrome

Trial page ClinicalTrials.govUpdated 6 Dec 2024

Version history

PepBank keeps every version of the data on this study. Status changes from Retraction Watch, Europe PMC and Crossref are listed with their source.

Version 2Current
11 Oct 2026, 00:04 UTC
Study results updated
Version 1
9 Oct 2026, 03:06 UTC
First added · source update from Europe PMC

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