4-Fluoroselegiline, or p-fluoro-L-deprenyl, is a substituted amphetamine designer drug.

4-Fluoroselegiline is a selective and irreversible inhibitor of monoamine oxidase B and monoaminergic activity enhancer.

[1][2][3] A radiolabelled derivative incorporating 18F is used to study MAO-B inhibition in both in vivo and in vitro experiments.

The levels of substituted amphetamine metabolites in the brain is three times higher following 4-fluoroselegiline administration compared to an equivalent dose of selegiline.

[2] Synonyms of 4-fluoroselegiline or 4-fluorodeprenyl (the racemic form) include Chinoin-175, Fludepryl, and SR-96516-A.