Therapeutic Effects of Glucagon-like Peptide-1 Receptor Agonists in Non-Alcoholic Fatty Liver Disease: A Systematic Review.

Non-alcoholic fatty liver disease (NAFLD), now increasingly termed metabolic dysfunction-associated steatotic liver disease (MASLD), is a growing cause of chronic liver disease with limited treatment options. Glucagon-like peptide-1 (GLP-1) receptor agonists, approved for type 2 diabetes and obesity, possess metabolic effects that may render them suitable for treating NAFLD and metabolic dysfunction-associated steatohepatitis (MASH). To evaluate the therapeutic effects of GLP-1 receptor agonists in adults with NAFLD, non-alcoholic steatohepatitis (NASH), MASLD, or MASH. PubMed, Scopus, Embase, and the Cochrane Library were systematically searched using keywords related to NAFLD and GLP-1 receptor agonists. Given heterogeneity in populations, designs, and outcomes, findings were synthesized narratively. The review is registered with PROSPERO (CRD420261337353). Twelve studies met the inclusion criteria. The most consistent outcome was a reduction in hepatic fat, seen with semaglutide, liraglutide, dulaglutide, and beinaglutide. Improvements in liver enzymes, particularly alanine aminotransferase, were less consistent and best regarded as supportive rather than definitive evidence of histological improvement. Histological benefits were strongest for steatohepatitis resolution in non-cirrhotic MASH. Fibrosis findings were mixed, with the greatest benefit in F2-F3 MASH and limited improvement in established cirrhosis. GLP-1 receptor agonists were generally well tolerated, with gastrointestinal symptoms the most common adverse effects. GLP-1 receptor agonists show promising liver-related benefits in NAFLD and MASH, particularly in obesity, type 2 diabetes, or earlier-stage disease. Their effects on advanced fibrosis and long-term outcomes remain uncertain, warranting larger, longer-term studies.