4-Fluoroselegiline, or p-fluoro-<small>L</small>-deprenyl, is a substituted amphetamine designer drug. It is the enantiopure <small>L</small>- enantiomer of 4-fluorodeprenyl and the 4-fluorinated derivative of selegiline (<small>L</small>-deprenyl).
4-Fluoroselegiline is a selective and irreversible inhibitor of monoamine oxidase B and monoaminergic activity enhancer.
A radiolabelled derivative incorporating <sup>18</sup>F is used to study MAO-B inhibition in both in vivo and in vitro experiments.
4-Fluorodeprenyl is metabolized to 4-fluoromethamphetamine and 4-fluoroamphetamine, both of which are active. The levels of substituted amphetamine metabolites in the brain is three times higher following 4-fluoroselegiline administration compared to an equivalent dose of selegiline.
Synonyms of 4-fluoroselegiline or 4-fluorodeprenyl (the racemic form) include Chinoin-175, Fludepryl, and SR-96516-A.