Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are widely used in the treatment of type 2 diabetes and obesity due to their metabolic effects. Emerging evidence suggests they may also have neuroprotective effects, indicating their potential as disease-modifying therapies in neurodegenerative disorders such as Alzheimer’s disease (AD) and Parkinson’s disease (PD). Preclinical studies in animal models have demonstrated that GLP-1RAs can reduce neuroinflammation, oxidative stress, neuronal apoptosis, and pathological protein aggregation, while enhancing glucose metabolism and mitochondrial function. This narrative review analyzed results from human clinical trials evaluating GLP-1RAs in AD and PD, based on a search of four databases (Web of Science, Medline, Embase, and Clinical Trials). The analysis included eleven studies. In AD, clinical trials suggest that GLP-1RAs such as liraglutide and semaglutide may enhance brain glucose metabolism, facilitate glucose transport across the blood–brain barrier, and benefit neuronal networks. However, most studies did not demonstrate improvements in cognitive functions or radiological markers. Short-term clinical trials of GLP-1RAs, including exenatide and lixisenatide, demonstrated promising effects on motor and selected non-motor symptoms in patients with PD, but their disease-modifying effects remain unproven. GLP-1RAs showed a favorable safety profile. Despite promising findings, small study populations, heterogeneous protocols, and short observation periods limit definitive conclusions. Further larger, long-term studies are needed, particularly to clarify the risk–benefit balance, weight control, and long-term outcomes.
Pilśniak et al. (2025) studied this question.