Volume 30, Issue 174, August 2026

Glucagon-like peptide 1 receptor agonists in obesity treatment: efficacy, safety and clinical implications

Sylwia Lepak^1♦, Zuzanna Irzyk¹, Dominika Ruszel¹, Emilia Goc¹, Julia Rogała¹, Katarzyna Markuszka¹, Kinga Polityńska¹, Klaudia Samuła¹, Martyna Sarzyńska¹, Mateusz Szabat²

¹Faculty of Medicine, Collegium Medicum, University of Rzeszów, Poland
²Clinical Provincial Hospital No. 2, Rzeszów, Poland

^♦Corresponding author
Sylwia Lepak, Faculty of Medicine, Collegium Medicum, University of Rzeszów, Poland

ABSTRACT

Background: Obesity is one of the leading causes of morbidity and mortality nowadays, with prevalence tripling since the 1970s. Lifestyle modification remains the cornerstone of treatment, but pharmacotherapy has emerged as a critical adjunct, including GLP-1R(glucagon-like peptide-1 receptor) agonists. Objective: To present the efficacy, safety, and clinical implications of GLP-1 receptor agonists in the treatment of obesity. Methods: A narrative review was based on articles available in PubMed, NIH, Wiley, The Lancet, and NEJM databases. Keywords included “obesity”, “GLP-1R agonists”, “semaglutide”, “liraglutide”, “tirzepatide”. Inclusion criteria encompassed randomized clinical trials, observational studies, metaanalyses, and review articles published in English between October 2018 and December 2025. Results: GLP-1 receptor agonists demonstrate significant weight loss efficacy. Semaglutide achieves weight loss of 11.4–13.9% at 68 weeks, and liraglutide produces 5.3–5.8% weight loss at 52–56 weeks. Tirzepatide, a dual GIP/GLP-1 agonist, demonstrates efficacy with even 17.8% weight loss at 72 weeks. Furthermore, these agents improve cardiometabolic parameters, such as blood pressure, lipid profiles, and glycemic control. Gastrointestinal adverse events, such as nausea, vomiting, diarrhea, and constipation, are common but generally mild. More serious adverse events are rare. Conclusions: GLP-1 receptor agonists are among the most effective options for the treatment of obesity. They help achieve clinically significant weight loss and improvements in metabolic parameters. There is a need for further research to investigate long-term safety and optimal treatment strategies.

Keywords: obesity, GLP-1R agonists, semaglutide, liraglutide, tirzepatide

Medical Science, 2026, 30, e148ms3856

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Published: 12 August 2026