PBT434 methanesulfonate is an orally active, potent α-synuclein aggregation inhibitor with the ability to cross the blood-brain barrier. Acting as an iron chelator, it modulates transcellular iron trafficking, inhibits iron-mediated redox activity, and prevents iron-mediated aggregation of α-synuclein. PBT434 methanesulfonate also safeguards against the loss of substantia nigra pars compacta neurons (SNpc), showing promise for Parkinson’s disease (PD) research.