Overall, the majority of the PD therapeutic compounds are intended or designed for dopaminergic activity or symptom relief, and only three of the 147 therapeutic drugs target mitochondrial activity as a mechanism of action...Nicotinamide riboside. This compound is a different form of vitamin B3, which in the brain promotes the formation of NAD+, which usually declines with aging and neurodegeneration. A phase I clinical trial studied the effects of nicotinamide riboside (NR) oral intake (1000 mg for 30 days) in individuals with PD (clinicaltrials.gov: NCT03816020). Overall, NR treatment was well tolerated, promoting increased NAD levels in the brain (MRI scan and CSF) and increased brain glucose metabolism. The clinical benefits were associated with increased NAD levels and increased mitochondrial activity. This study advanced to phase II where the PD patients will take NR for up to 1 year; the results of this study are expected in 2024.