N-sec-Butyltryptamine (NsBT) is a psychoactive drug of the tryptamine family related to psychedelics like dimethyltryptamine (DMT).
NsBT was briefly described by Alexander Shulgin in his 1997 book TiHKAL (Tryptamines I Have Known and Loved). According to Shulgin, NsBT is active at a dose of 25 to 75mg orally and has a short-lived duration. Its effects included a generalized and somewhat diffuse intoxication, intellectual excitement, modest sensory enhancements, and "a lot of erotic horniness". However, no "plus-three" ratings occurred on the Shulgin Rating Scale.
Shulgin has said that along with N-tert-butyltryptamine (NtBT), it is one of only two N-mono-substituted tryptamines with known psychoactivity. He also said that N-mono-substituted tryptamines might be GHB-like intoxicants devoid of psychedelic effects. However, N-methyltryptamine (NMT) has been reported to produce psychedelic effects.
Analogues of NsBT include 5-MeO-NsBT, N-methyltryptamine (NMT), N-ethyltryptamine (NET), N-isopropyltryptamine (NiPT), N-benzyltryptamine (NBnT), N-methyl-N-sec-butyltryptamine (MsBT), among others.
NsBT is not a controlled substance in Canada as of 2025.