The NIH Clinical Trial published information on a study provided by Arkadir David of the Hadassah Medical Organization. The study took 60 participants and ran a phase II single center, randomized, double blind and placebo controlled study assessing the safety, tolerability, and effects of progressively increased dose of oral mannitol in PD. The study began in November 2018 and will end in December 2020. There were 60 Participants of both genders and aged 40 to 75 years. The study assessed the safety of mannitol by the number of treatment-related adverse events and significant changes in vital signs. Tolerability was tested by the level of discomfort. Other changes in participants that were monitored included changes in constipation assessment; Montreal Cognitive Assessment; Brief Smell Identification; change in levodopa-equivalent dose units; change in non-motor symptoms of PD scale and the change in the ratio of total-to-proteinase K-resistant a-syn in red blood cells measured by enzyme-linked immunosorbent assay. Results of this study have not yet been posted.