N-Isopropyltryptamine (NiPT) is a serotonin receptor agonist of the tryptamine family.
According to Alexander Shulgin, no active dose level of NiPT has yet been found in humans.
NiPT acts as a potent full agonist of the serotonin 5-HT<sub>2A</sub> receptor, whereas it is inactive as an agonist of the serotonin 5-HT<sub>1A</sub> receptor. The drug is also a weak serotonin reuptake inhibitor.
Analogues of NiPT include N-methyltryptamine (NET), N-ethyltryptamine, N-sec-butyltryptamine (NsBT), N-tert-butyltryptamine (NtBT), and diisopropyltryptamine (DiPT), among others.
Some derivatives of NiPT include 4-HO-NiPT, 5-HO-NiPT, and 5-MeO-NiPT, among others. 5-MeO-NiPT is likewise a serotonin receptor agonist. It is a potent full agonist or high-efficacy partial agonist of the serotonin 5-HT<sub>1A</sub>, 5-HT<sub>2A</sub>, 5-HT<sub>2B</sub>, and 5-HT<sub>2C</sub> receptors. In contrast to 5-MeO-NMT and 5-MeO-NET, which are inactive in the test, 5-MeO-NiPT induces the head-twitch response, a behavioral proxy of psychedelic effects, in rodents, and hence may be hallucinogenic in humans. 4-HO-NiPT is also a serotonin receptor agonist and produces the head-twitch response in rodents as well.
NiPT is not a controlled substance in Canada as of 2025.