Determining whether some or all the described mechanisms of action of GLP-1 receptor agonists alter the natural history of PD, or if they merely produce symptomatic effects upon exposure, is a challenge for clinical trials.27Knowing this, the present meta-analysis also sought to investigate whether, after an 8- to 12-week wash-out period, there would be lower levels of impairment in the scores on part III of the MDS-UPDRS. Here, GLP1R is linked to Parkinson disease.