The revelation that MPP+ causes the death of dopaminergic neurons and ultimately induces symptoms of Parkinson's disease was crucial in establishing the lack of dopamine as central to Parkinson's disease.[1] Levodopa or L-DOPA came into common use as an anti-Parkinson's medication thanks to the results brought about by research using MPP+.[2] Further medications are in trial to treat the progression of the disease itself as well as the motor and non-motor symptoms associated with Parkinson's, with MPP+ still being widely used in early trials to test efficacy.[12]