4-HO-NALT, also known as 4-hydroxy-N-allyltryptamine, is a tryptamine derivative developed by modification of norpsilocin (4-HO-NMT). It produces a head-twitch response in mice consistent with psychedelic-like activity, as do the corresponding ethyl, propyl, isopropyl, and benzyl derivatives (4-HO-NET, 4-HO-NPT, 4-HO-NiPT, and 4-HO-NBnT, respectively), but the bulkier t-butyl and cyclohexyl derivatives are inactive.