Butylamphetamine (code name PAL-90; also known as N-butylamphetamine or NBA) is a psychostimulant of the substituted amphetamine family which was never marketed.

[2][3] The drug has been found to be inactive as a dopamine reuptake inhibitor or releasing agent (IC50Tooltip half-maximal inhibitory concentration and EC50Tooltip half-maximal effective concentration > 10,000 nM, respectively).

[1] With regard to structure–activity relationships, the potency of N-substituted amphetamine derivatives decreases with increasing chain length in terms of both in vitro and in vivo activity.

[13][14] It can be metabolized by CYP2D6 via ring hydroxylation similarly to amphetamine.

[15][16] In addition, butylamphetamine can be N-dealkylated into amphetamine (6–9% excreted in urine after 24 hours).