Psilocin is a substituted tryptamine alkaloid and a serotonergic psychedelic substance. It is present in most psychedelic mushrooms together with its phosphorylated counterpart psilocybin. Psilocin is a Schedule I drug under the Convention on Psychotropic Substances. Acting on the 5-HT2A receptors, psilocin modulates the production and reuptake of serotonin. The mind-altering effects of psilocin are highly variable and subjective and resemble those of LSD and DMT.
5-Methoxy-alpha-ethyltryptamine (5-MeO-α-ET) is a psychoactive drug and member of the tryptamine chemical class. It produces psychedelic and stimulant effects.
5-Fluoro-α-methyltryptamine, also known as PAL-544, is a putative stimulant, entactogen, and psychedelic tryptamine derivative related to α-methyltryptamine (αMT). It has been found to act as a well-balanced serotonin-norepinephrine-dopamine releasing agent, a 5-HT2A receptor agonist, and a potent and specific MAO-A inhibitor. which suggests that 5-fluoro-αMT could be an active psychedelic in humans, although it is not known to have been tested in humans and could be dangerous due to its strong inhibition of MAO-A.
5-Fluoro-N,N-dimethyltryptamine is a tryptamine derivative related to compounds such as 5-bromo-DMT and 5-MeO-DMT. Fluorination of psychedelic tryptamines either reduces or has little effect on 5-HT2A/C receptor affinity or intrinsic activity, although 6-fluoro-DET is inactive as a psychedelic despite acting as a 5-HT2A agonist, while 4-fluoro-5-methoxy-DMT is a much stronger agonist at 5-HT1A than 5-HT2A.
5-Methoxy-7,N,N-trimethyltryptamine (5-MeO-7,N,N-TMT, 5-MeO-7-TMT), is a tryptamine derivative which acts as a partial agonist at the 5-HT2 serotonin receptors, with an EC50 of 63.9 nM and an efficacy of 66.2% at 5-HT2A (vs 5-HT), and weaker activity at 5-HT2B and 5-HT2C. In animal tests, both 7,N,N-TMT and 5-MeO-7,N,N-TMT produced behavioural responses similar to those of psychedelic drugs such as DMT and 5-MeO-DMT, but compounds with larger 7-position substituents such as 7-ethyl-DMT and 7-bromo-DMT did not produce psychedelic-appropriate responding despite high 5-HT2 receptor binding affinity, suggesting these may be antagonists or weak partial agonists for the 5-HT2 receptors. The related compound 7-MeO-MiPT (cf. 5-MeO-MiPT) was also found to be inactive, suggesting that the 7-position has poor tolerance for bulky groups at this position, at least if agonist activity is desired.
4-Fluoro-5-Methoxy-N,N-dimethyltryptamine (4-F-5-MeO-DMT) was first described by David E. Nichols team in 2000. It is a potent 5-HT1A agonist. Substitution with the 4-fluorine markedly increased 5-HT1A selectivity over 5-HT2A/2C receptors with potency greater than that of the 5-HT1A agonist 8-OH-DPAT.
5-MeO-NBpBrT is a N-substituted member of the methoxytryptamine family of compounds. Like other such compounds it acts as an antagonist for the 5-HT2A receptor, with a claimed 100x selectivity over the closely related 5-HT2C receptor. While N-benzyl substitution of psychedelic phenethylamines often results in potent 5-HT2A agonists, it had been thought that N-benzyl tryptamines show much lower efficacy and are either very weak partial agonists or antagonists at 5-HT2A, though more recent research has shown stronger agonist activity for 3-substituted benzyl derivatives. Extending the benzyl group to a substituted phenethyl can also recover agonist activity in certain cases.
O-4310 (1-isopropyl-6-fluoro-psilocin) is a tryptamine derivative developed by Organix Inc which acts as a serotonin receptor agonist. It is claimed to have an EC50 of 5nM at 5-HT2A with 89% efficacy vs 5-HT, and 100x selectivity over 5-HT2C, while being apparently inactive at the 5-HT2B antitarget.
5-Chloro-α-methyltryptamine (5-Chloro-αMT), also known as PAL-542, is a tryptamine derivative related to α-methyltryptamine (αMT) and one of only a few known specific serotonin-dopamine releasing agents (SDRAs). It has been investigated in animals as a potential treatment for cocaine dependence. The EC50 values of 5-chloro-αMT in evoking the in vitro release of serotonin (5-HT), dopamine (DA), and norepinephrine (NE) in rat synaptosomes were reported as 16 nM, 54 nM, and 3434 nM, with an NE/DA ratio of 63.6 and a DA/5-HT ratio of 3.38, indicating that it is a highly specific and well-balanced SDRA. However, 5-chloro-αMT has also been found to act as a potent full agonist of the 5-HT2A receptor, with an EC50 value of 6.27 nM and an efficacy of 105%, and almost assuredly acts as a potent agonist of other serotonin receptors as well.
5-MeO-MET (5-Methoxy-N-methyl-N-ethyltryptamine) is a relatively rare designer drug from the substituted tryptamine family, related to compounds such as N-methyl-N-ethyltryptamine and 5-MeO-DMT. It was first synthesised in the 1960s and was studied to a limited extent, but was first identified on the illicit market in June 2012 in Sweden. It was made illegal in Norway in 2013, and is controlled under analogue provisions in numerous other jurisdictions.
7-Chloro-α-methyltryptamine (7-Cl-AMT) is a tryptamine derivative with stimulant effects, invented in the 1960s. It is a weak monoamine oxidase inhibitor but its pharmacology has not otherwise been studied by modern techniques, though several closely related compounds are known to act as serotonin–dopamine releasing agents and agonists of the 5-HT2A receptor.
5-Fluoro-α-ethyltryptamine (5-F-AET) is a tryptamine derivative which acts as a serotonin–dopamine releasing agent and agonist of the 5-HT2A receptor.
5-Fluoro-EPT (5F-EPT, 5-fluoro-N-ethyl-N-propyltryptamine) is a psychedelic tryptamine derivative related to drugs such as EPT and 5-MeO-EPT. It acts as a potent full agonist at the 5-HT2A receptor with an EC50 of 5.54 nM and an efficacy of 104% (compared to serotonin). It produces a head-twitch response in animal studies, and is claimed to have antidepressant activity.
5-Fluoro-DET is a tryptamine derivative related to drugs such as DET and 5-MeO-DET. It acts as an inhibitor of the enzyme myeloperoxidase, and is also thought to be an agonist at the 5-HT2A receptor.
6-Fluoro-DET is a substituted tryptamine derivative related to drugs such as DET and 5-fluoro-DET. It acts as a partial agonist at the 5-HT2A receptor, but while it produces similar physiological effects to psychedelic drugs, it does not appear to produce psychedelic effects itself even at high doses. For this reason it saw some use as an active placebo in early clinical trials of psychedelic drugs but was regarded as having little use otherwise, though more recent research into compounds such as AL-34662, TBG and AAZ-A-154 has shown that these kind of non-psychedelic 5-HT2A agonists can have various useful applications.
4-Hydroxy-N-propyl-N-isopropyltryptamine (4-HO-PiPT, Piprocin) is a substituted tryptamine derivative which is claimed to have psychedelic effects. It acts as a 5-HT2A receptor agonist, with an EC50 of 13.8 nM and an efficacy of 104.8% (vs 5-HT), and has been sold as a designer drug, first being identified in 2021 in British Columbia, Canada.
7-F-5-MeO-MET (5-MeO-7-F-MET, 5-Methoxy-7-fluoro-N-methyl-N-ethyltryptamine) is a tryptamine derivative which acts as a serotonin receptor agonist selective for the 5-HT2 subtypes, with a pEC50 of 8.71 at 5-HT2A, vs 8.25 at 5-HT2B and 7.69 at 5-HT2C. In animal tests it produced the most potent head-twitch response of a range of related fluorinated tryptamine derivatives tested, though still with slightly lower potency than psilocybin.
5-TFM-DMT (5-(trifluoromethyl)-DMT, 5-CF3-DMT, 5-(trifluoromethyl)-N,N-dimethyltryptamine) is a putative psychedelic tryptamine derivative related to drugs such as 5-MeO-DMT, 5-Fluoro-DMT, and 5-TFMO-DMT. It acts as a partial agonist at the 5-HT2A receptor, with an EC50 of 185.7 nM and an efficacy of 28.7% (vs 5-HT), and a full agonist at 5-HT2C with an EC50 of 89.7 nM and an efficacy of 88.8%, and no significant activity at 5-HT2B.
