GCG and Parkinson disease: On the other hand, antidiabetic drugs could have a beneficial and neuroprotective effect, since certain antidiabetic drugs have shown a potential neuroprotective effect in PD, especially the glucagon-like peptide-1 (GLP-1) receptor agonists and dipeptidyl peptidase-4 inhibitors (DPP-4is).57Preliminary studies58, 59on exenatide and lixisenatide, both GLP-1 receptor agonists, showed potential but modest benefits in motor symptoms throughout 12 months in PD patients.