4-PPBP maleate is a selective σ1 receptor agonist used primarily as a research chemical in pharmaceutical development, particularly for studies on central nervous system disorders. It acts as an intermediate in the synthesis of compounds with neuroprotective properties and is commonly applied in preclinical research to investigate σ1 receptor modulation, which influences neurotransmitter systems including dopamine, relevant to Parkinson's disease and schizophrenia. It is also employed in analytical chemistry for reference standards and method development owing to its defined receptor binding profile.