4-HO-NET, also known as 4-hydroxy-N-ethyltryptamine, is a serotonin receptor modulator and putative psychedelic drug of the tryptamine and 4-hydroxytryptamine families related to norpsilocin (4-HO-NMT). It was not included by Alexander Shulgin in his 1997 book TiHKAL (Tryptamines I Have Known and Loved) and its properties and effects in humans are unknown. The drug acts as a non-selective serotonin receptor agonist, including of the serotonin 5-HT<sub>2A</sub> receptor. It produces the head-twitch response, a behavioral proxy of psychedelic effects, in rodents, albeit with about 13-fold lower potency than psilocin (4-HO-DMT). Unlike 4-HO-NET, norpsilocin is notably inactive in this test. In addition to its psychedelic-like effects, 4-HO-NET produces hypolocomotion and hypothermia in rodents. 4-HO-NET was first described in the scientific literature by Alexander Sherwood and colleagues by 2024.