Stimulants are a class of drugs that increase the activity of the brain and the spinal cord. They are used for various purposes, such as enhancing alertness, attention, motivation, cognition, mood, and physical performance. Some of the most common stimulants are caffeine, nicotine, amphetamines, cocaine, and modafinil.
5-HT receptors, 5-hydroxytryptamine receptors, or serotonin receptors, are a group of G protein-coupled receptor and ligand-gated ion channels found in the central and peripheral nervous systems. They mediate both excitatory and inhibitory neurotransmission. The serotonin receptors are activated by the neurotransmitter serotonin, which acts as their natural ligand.
5-Hydroxytryptophan (5-HTP), also known as oxitriptan, is a naturally occurring amino acid and chemical precursor as well as a metabolic intermediate in the biosynthesis of the neurotransmitter serotonin.
2,5-Dimethoxy-4-iodoamphetamine (DOI) is a psychedelic drug and a substituted amphetamine. Unlike many other substituted amphetamines, however, it is not primarily a stimulant. DOI has a stereocenter and R-(−)-DOI is the more active stereoisomer. In neuroscience research, [125I]-R-(−)-DOI is used as a radioligand and indicator of the presence of 5-HT2A serotonin receptors. DOI's effects have been compared to LSD, although there are differences that experienced users can distinguish. Besides the longer duration, the trip tends to be more energetic than an LSD trip, with more body load and a different subjective visual experience. The after effects include residual stimulation and difficulty sleeping, which, depending on the dose, may persist for days. While rare, it is sometimes sold as a substitute for LSD, or even sold falsely as LSD, which may be dangerous because DOI does not have the same established safety profile as LSD.
4-Fluoroamphetamine, also known as para-fluoroamphetamine (PFA) is a psychoactive research chemical of the phenethylamine and substituted amphetamine chemical classes. It produces stimulant and entactogenic effects. As a recreational drug, 4-FA is sometimes sold along with related compounds such as 2-fluoroamphetamine and 4-fluoromethamphetamine.
4-Methylthioamphetamine (4-MTA) is a designer drug of the substituted amphetamine class developed in the 1990s by a team led by David E. Nichols, an American pharmacologist and medical chemist, at Purdue University. It acts as a non-neurotoxic highly selective serotonin releasing agent (SSRA) in animals. 4-MTA is the methylthio derivative of amphetamine.
Benzofuranylpropylaminopentane is a drug with an unusual monoamine-release potentiating mechanism of action. It can loosely be grouped with the stimulant or antidepressant drug families, but its mechanism of action is quite different.
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.
para-Chloroamphetamine (PCA), also known as 4-chloroamphetamine (4-CA), is a substituted amphetamine and monoamine releaser similar to MDMA, but with substantially higher neurotoxicity, thought to be due to the unrestrained release of both serotonin and dopamine by a metabolite. It is used as a neurotoxin by neurobiologists to selectively kill serotonergic neurons for research purposes, in the same way that 6-hydroxydopamine is used to kill dopaminergic neurons.
MDAI (5,6-methylenedioxy-2-aminoindane) is a drug developed in the 1990s by a team led by David E. Nichols at Purdue University. It acts as a non-neurotoxic and highly selective serotonin releasing agent (SSRA) in vitro and produces entactogen effects in humans.
Amfonelic acid is a research chemical and dopaminergic stimulant with antibiotic properties. Although limited clinical trials have been conducted, it's primarily used in scientific research.
2-Aminotetralin (2-AT), also known as 1,2,3,4-tetrahydronaphthalen-2-amine (THN), is a stimulant drug with a chemical structure consisting of a tetralin group combined with an amine.
para-Bromoamphetamine (PBA), also known as 4-bromoamphetamine (4-BA), is an amphetamine derivative which acts as a serotonin-norepinephrine-dopamine releasing agent (SNDRA) and produces stimulant effects.
meta-Methoxyamphetamine (MMA), also known as 3-methoxyamphetamine (3-MA), is a stimulant drug from the amphetamine family. It has similar effects in animal drug discrimination tests to the more widely known derivative 4-methoxyamphetamine (PMA), although with a slightly different ratio of monoamine release, being a combined serotonin, dopamine, and norepinephrine releasing agent rather than a fairly selective serotonin releaser like PMA. 3-Methoxyamphetamine has similarly appeared on the illicit market as a designer drug alternative to MDMA, although far more rarely than its infamous positional isomer. It produces gepefrine, a cardiac stimulant, as one of its major metabolites.
6-Chloro-2-aminotetralin (6-CAT) is a drug which acts as a selective serotonin releasing agent (SSRA) and is a putative entactogen in humans. It is a rigid analogue of para-chloroamphetamine (PCA).
threo-4-Methylmethylphenidate (4-MeTMP) is a stimulant drug related to methylphenidate. It is slightly less potent than methylphenidate and has relatively low efficacy at blocking dopamine reuptake despite its high binding affinity, which led to its investigation as a possible substitute drug for treatment of stimulant abuse. On the other hand, several other simple ring-substituted derivatives of threo-methylphenidate such as the 4-fluoro and 3-chloro compounds are more potent than methylphenidate both in efficacy as dopamine reuptake inhibitors and in animal drug discrimination assays.
Osemozotan (MKC-242) is a selective 5-HT1A receptor agonist with some functional selectivity, acting as a full agonist at presynaptic and a partial agonist at postsynaptic 5-HT1A receptors. 5-HT1A receptor stimulation influences the release of various neurotransmitters including serotonin, dopamine, norepinephrine, and acetylcholine. 5-HT1A receptors are inhibitory G protein-coupled receptor. Osemozotan has antidepressant, anxiolytic, antiobsessional, serenic, and analgesic effects in animal studies, and is used to investigate the role of 5-HT1A receptors in modulating the release of dopamine and serotonin in the brain, and their involvement in addiction to abused stimulants such as cocaine and methamphetamine.
4-Chlorophenylisobutylamine, also known as 4-chloro-α-ethylphenethylamine, is an entactogen and stimulant drug of the phenethylamine class. It is an analogue of para-chloroamphetamine (PCA) where the alpha position methyl has been replaced with an ethyl group.
A monoamine reuptake inhibitor (MRI) is a drug that acts as a reuptake inhibitor of one or more of the three major monoamine neurotransmitters serotonin, norepinephrine, and dopamine by blocking the action of one or more of the respective monoamine transporters (MATs), which include the serotonin transporter (SERT), norepinephrine transporter (NET), and dopamine transporter (DAT). This in turn results in an increase in the synaptic concentrations of one or more of these neurotransmitters and therefore an increase in monoaminergic neurotransmission.
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.
