"N"-Isopropyltryptamine (NiPT) is a serotonin receptor agonist of the tryptamine family. It acts as a potent full agonist of the serotonin 5-HT2A receptor, whereas it is inactive as an agonist of the serotonin 5-HT1A receptor. The drug is also a weak serotonin reuptake inhibitor. According to Alexander Shulgin, no active dose level of NiPT has been found in humans.
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-HT1A, 5-HT2A, 5-HT2B, and 5-HT2C 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.