Tags: Drug.
4-Fluoroamphetamine (4-FA; PAL-303; Flux) also known as para-fluoroamphetamine (PFA) is a psychoactive drug and research chemical of the phenethylamine and substituted amphetamine chemical classes. It produces stimulant and possibly entactogenic effects. 4-FA is sometimes sold as a designer drug along with related compounds such as 2-fluoroamphetamine and 4-fluoromethamphetamine.