Liraglutide Selectively Reduces Belly Fat While Preserving Lean Mass in Just 18 Days

Short-term liraglutide (18 days) selectively reduced android and trunk fat while preserving lean and bone mass, with decreased C-peptide and modestly increased IGF-1 in patients with type 2 diabetes.

Gutierrez de Piñeres, Valeria et al.·Diabetes·2026·
RPEP-152442026RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Not classified
Evidence
Not graded
Sample
Not reported

What This Study Found

Liraglutide over 18 days reduced total mass (p=0.04), android fat % (p=0.04), and trunk fat (p=0.04) with no lean/bone changes. C-peptide decreased (p=0.026), IGF-1 modestly increased (p=0.002). No MAFI axis changes.

Key Numbers

How They Did This

Randomized double-blind placebo-controlled crossover trial in 20 adults with T2D, 18-day liraglutide (up to 1.8 mg/day) vs placebo with washout, DXA regional body composition, and MAFI hormone panel.

Why This Research Matters

Knowing that fat loss starts quickly and targets the most dangerous fat (abdominal) while sparing muscle provides early reassurance for patients starting GLP-1 therapy.

The Bigger Picture

The selective android fat loss within 18 days suggests GLP-1 drugs preferentially mobilize the metabolically dangerous visceral fat depot first.

What This Study Doesn't Tell Us

Very short (18 days). Small sample (n=20). May not predict longer-term composition changes. Crossover design may have carryover effects despite washout.

Questions This Raises

  • ?Does the selective android fat loss persist with longer treatment?
  • ?Is the IGF-1 increase a compensatory mechanism protecting lean mass?
  • ?Would these body composition changes differ at higher GLP-1 doses?

Trust & Context

Key Stat:
Belly fat first Just 18 days of liraglutide selectively reduced the most dangerous fat (android/trunk) while leaving muscle and bone untouched
Evidence Grade:
Small but well-designed randomized crossover RCT with DXA body composition. Limited by short duration and sample size.
Study Age:
Published in 2025.
Original Title:
Effects of liraglutide treatment for 18 days on metabolic parameters, regional body composition and the myostatin-activin-follistatin-IGF-1 axis: Results from an exploratory, randomized, placebo-controlled, crossover study.
Published In:
Diabetes, obesity & metabolism, 28(2), 1258-1265 (2026)
Database ID:
RPEP-15244

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study
What do these levels mean? →

Frequently Asked Questions

Does liraglutide burn belly fat specifically?

Yes. Within just 18 days, this study found liraglutide selectively reduced android (belly) and trunk fat while leaving muscle and bone mass completely unchanged.

Will I lose muscle on GLP-1 drugs?

Not in the short term. This careful 18-day study with DXA scanning showed no lean mass or bone changes. The body appears to selectively burn fat stores first.

Read More on RethinkPeptides

Related articles coming soon.

Cite This Study

RPEP-15244·https://rethinkpeptides.com/research/RPEP-15244

APA

Gutierrez de Piñeres, Valeria; Tamayo-Torres, Claudia S; Ramirez-Cisneros, Arantxa; Kavelidou, Marianthi; Stefanakis, Konstantinos; Mantzoros, Christos S. (2026). Effects of liraglutide treatment for 18 days on metabolic parameters, regional body composition and the myostatin-activin-follistatin-IGF-1 axis: Results from an exploratory, randomized, placebo-controlled, crossover study.. Diabetes, obesity & metabolism, 28(2), 1258-1265. https://doi.org/10.1111/dom.70313

MLA

Gutierrez de Piñeres, Valeria, et al. "Effects of liraglutide treatment for 18 days on metabolic parameters, regional body composition and the myostatin-activin-follistatin-IGF-1 axis: Results from an exploratory, randomized, placebo-controlled, crossover study.." Diabetes, 2026. https://doi.org/10.1111/dom.70313

RethinkPeptides

RethinkPeptides Research Database. "Effects of liraglutide treatment for 18 days on metabolic pa..." RPEP-15244. Retrieved from https://rethinkpeptides.com/research/gutierrez-2026-effects-of-liraglutide-treatment

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkPeptides research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.