Analysis of 6,239 adults finds semaglutide cut weight, waist size and CRP

A meta-analysis of 6,239 adults with overweight or obesity but without diabetes found that injected semaglutide reduced body weight, waist circumference and a marker of inflammation by more than placebo, according to a review published August 31, 2026 in the International Journal of Obesity ^[1].

The analysis pooled nine randomized controlled trials — 4,203 participants assigned to semaglutide and 2,036 to placebo — with treatment periods ranging from 52 to 104 weeks. The reviewers searched PubMed, the Cochrane Library and ClinicalTrials.gov through November 15, 2025, and registered the review in advance ^[1]. The drug studied was subcutaneous semaglutide, the injected form (the molecule sold as Ozempic and Wegovy); oral semaglutide was not included ^[1].

Pooled results showed semaglutide was associated with a 12.04-percentage-point greater reduction in body weight than placebo. Under trial-policy analyses that estimate effects under more idealized trial conditions, that gap was 14.13 percentage points. Waist circumference fell 9.36 cm more with semaglutide, and C-reactive protein (CRP), a general marker of inflammation, fell 40.90 percentage points more than with placebo ^[1].

One included trial, STEP UP, tested a 7.2 mg dose — higher than the 2.4 mg used in most of the studies — and showed larger effects: a 14.80-percentage-point greater weight reduction and a 50.00-percentage-point greater CRP reduction than placebo. The authors identified STEP UP as the main source of inconsistency between trials (statistical heterogeneity of 74% for weight loss and 54% for CRP) and said the apparent dose-related pattern "remains exploratory," because it rests largely on a single trial ^[1].

Serious adverse events did not differ statistically between the semaglutide and placebo groups overall (P = 0.55). When the reviewers removed one heart failure trial that had lower semaglutide event rates, the pooled risk ratio for serious adverse events rose to 1.31 and became statistically significant (P = 0.03). The authors cautioned that this sensitivity finding may reflect differences between the patient populations in the trials and should be interpreted cautiously ^[1].

The review lists its own limits: only one trial for the 7.2 mg dose, treatment lengths that varied across studies, clinical and methodological differences among the trials, and no data on other inflammatory markers such as interleukin-6 or TNF-alpha. Safety beyond the length of the included trials remains uncertain ^[1].

Why it matters for patients

This is a summary of previously completed trials, not a new study of a new drug. The numbers describe average differences between groups, so they do not predict what any one person will experience ^[1].

The review reports that waist circumference and CRP improved alongside weight loss. It does not establish that those changes were independent of the weight lost; whether the CRP reduction came from weight loss itself or from a separate drug effect is not addressed in the analysis ^[1].

Anyone taking the 2.4 mg dose should not read this as proof that 7.2 mg is better established. The authors call the higher-dose evidence exploratory and based largely on a single trial, and they say it requires confirmation ^[1].

The safety signal in the sensitivity analysis is a group-level observation drawn from trials that enrolled different kinds of patients, including a heart failure population. The authors say it should be treated carefully rather than as a settled finding ^[1].

Nothing in the review changes the doses or uses that regulators have approved, and it does not compare semaglutide with tirzepatide or with any other weight-management drug ^[1].

What happens next

The review calls for longer-term trials to assess multi-year safety and benefits across diverse patient groups, and says the 7.2 mg results need confirmation in further studies. No dates or trial schedules have been disclosed ^[1].