Research
Mixed
GLP-1 receptor agonists and incretin co-agonists reduce total body weight primarily through adipose tissue loss, but this process involves an absolute reduction in lean mass (skeletal muscle) that typically accounts for 20–30% of the total weight lost.
If you are taking GLP-1 medications, expect to lose some muscle along with fat. To minimize this, prioritize resistance training and adequate protein intake. This helps preserve strength and metabolic health despite the inevitable lean mass reduction.
GoodQualifiesHIGH confidence
Evidence from preclinical studies and randomized clinical trials indicates that while GLP-1-based therapies predominantly reduce adipose tissue, including visceral and ectopic depots, but they also produce absolute reductions in lean mass, generally representing 20–30% of total weight loss.
Why this rating
Based on a review of multiple preclinical models and RCTs, though the review notes methodological heterogeneity.
Source
The Influence of Glucagon-like Peptide-1 Receptor Agonists and Other Incretin Hormone Agonists on Body Composition
Lampros Chrysavgis et al. · International Journal of Molecular Sciences · 2025
DOI 10.3390/ijms262412130
narrative_reviewCited 4×
Read the paper DOI resolved against Crossref · corpus check 2026-06-10
Related findings · Mixed
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