Empathogens or entactogens are a class of psychoactive drugs that induce the production of experiences of emotional communion, oneness, relatedness, emotional openness—that is, empathy or sympathy—as particularly observed and reported for experiences with 3,4-methylenedioxymethamphetamine (MDMA). This class of drug is distinguished from the classes of hallucinogen or psychedelic, and amphetamine or stimulants. Major members of this class include MDMA, MDA, MDEA, MDOH, MBDB, 5-APB, 5-MAPB, 6-APB, 6-MAPB, methylone, mephedrone, GHB, αMT, and αET, MDAI among others. Most entactogens are phenethylamines and amphetamines, although several, such as αMT and αET, are tryptamines. When referring to MDMA and its counterparts, the term MDxx is often used. Entactogens are sometimes incorrectly referred to as hallucinogens or stimulants, although many entactogens such as ecstasy exhibit psychedelic or stimulant properties as well.
3,4-Methylenedioxyamphetamine (MDA), sometimes referred to as “sass,” is an empathogen-entactogen, stimulant, and psychedelic drug of the amphetamine family that is encountered mainly as a recreational drug. In its pharmacology, MDA is a serotonin–norepinephrine–dopamine releasing agent (SNDRA). In most countries, the drug is a controlled substance and its possession and sale are illegal.
α-Ethyltryptamine, also known as etryptamine, is an entactogen and stimulant drug of the tryptamine family. It was originally developed and marketed as an antidepressant under the brand name Monase by Upjohn in the 1960s before being withdrawn due to toxicity.
Methylone, also known as 3,4-methylenedioxy-N-methylcathinone (MDMC), is an empathogen and stimulant psychoactive drug. It is a member of the amphetamine, cathinone and methylenedioxyphenethylamine classes.
Naphthylaminopropane, also known as naphthylisopropylamine (NIPA), is an experimental drug that was under investigation for the treatment of alcohol and stimulant addiction.
para-Chloroamphetamine (PCA), also known as 4-chloroamphetamine (4-CA), is a serotonin–norepinephrine–dopamine releasing agent (SNDRA) and serotonergic neurotoxin of the amphetamine family. It is used in scientific research in the study of the serotonin system, as a serotonin releasing agent (SRA) at lower doses to produce serotonergic effects, and as a serotonergic neurotoxin at higher doses to produce long-lasting depletions of serotonin.
MDAI, also known as 5,6-methylenedioxy-2-aminoindane, is an entactogen drug of the 2-aminoindane group which is related to MDMA and produces similar subjective effects.
A monoamine releasing agent (MRA), or simply monoamine releaser, is a drug that induces the release of one or more monoamine neurotransmitters from the presynaptic neuron into the synapse, leading to an increase in the extracellular concentrations of the neurotransmitters and hence enhanced signaling by those neurotransmitters. The monoamine neurotransmitters include serotonin, norepinephrine, and dopamine; monoamine releasing agents can induce the release of one or more of these neurotransmitters.
A serotonin releasing agent (SRA) is a type of drug that induces the release of serotonin into the neuronal synaptic cleft. A selective serotonin releasing agent (SSRA) is an SRA with less significant or no efficacy in producing neurotransmitter efflux at other types of monoamine neurons, including dopamine and norepinephrine neurons.
A dopamine releasing agent (DRA) is a type of drug which induces the release of dopamine in the body and/or brain.
A serotonin–dopamine releasing agent (SDRA) is a type of drug which induces the release of serotonin and dopamine in the body and/or brain.
4-Methylamphetamine is a stimulant and anorectic drug of the phenethylamine and amphetamine chemical classes.
α-Methyldopamine (α-Me-DA), also known as 3,4-dihydroxyamphetamine or as catecholamphetamine, is a research chemical of the catecholamine and amphetamine families. It is a monoamine releasing agent and a metabolite of MDMA and MDA. The bis-glutathionyl metabolite of α-methyldopamine is slightly neurotoxic when directly injected into the brain's ventricles.
3,4-Dimethoxy-N-methylamphetamine (DMMA) is a psychoactive drug and research chemical of the phenethylamine and amphetamine chemical classes. It appears to act as a serotonin–norepinephrine–dopamine releasing agent (SNDRA), although it is significantly less potent than MDMA.
5-MAPB, also known as 5-(N-methyl-2-aminopropyl)benzofuran, is an entactogen and designer drug of the amphetamine family that is similar to MDMA in its structure and effects.
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%. It is likely to act as a potent agonist of other serotonin receptors as well.
2,4,5-Trihydroxymethamphetamine is a neurotoxin and a metabolite of MDMA. It has structural similarity to the dopamine neurotoxin 6-hydroxydopamine, and produces lasting serotonin deficits when administered centrally.
3,4-Dihydroxymethamphetamine, or 3,4-dihydroxy-N-methylamphetamine, also known as α-methylepinine or α,N-dimethyldopamine, is the major metabolite of 3,4-methylenedioxy-N-methylamphetamine (MDMA). It is formed from MDMA by O-demethylation via cytochrome P450 enzymes including CYP2D6 as well as CYP1A2 and CYP3A4. Like MDMA, HHMA is a monoamine releasing agent.
(R)-3,4-Methylenedioxy-N-methylamphetamine ((R)-MDMA), also known as (R)-midomafetamine or as levo-MDMA, is the (R)- or levorotatory (l-) enantiomer of 3,4-methylenedioxy-N-methylamphetamine (MDMA; midomafetamine; "ecstasy"), a racemic mixture of (R)-MDMA and (S)-MDMA. Like MDMA, (R)-MDMA is an entactogen or empathogen. It is taken by mouth.
4-Hydroxy-3-methoxyamphetamine (HMA), also known as 3-O-methyl-α-methyldopamine, is an active metabolite of 3,4-methylenedioxymethamphetamine (MDMA). It is substantially less potent than MDMA or 3,4-methylenedioxyamphetamine (MDA) as a monoamine releasing agent in vitro. Nonetheless, HMA has been found to induce the release of serotonin, norepinephrine, and dopamine with EC50Tooltip half-maximal effective concentration values of 897 nM, 694 nM, and 1450–3423 nM, respectively, and hence acts as a lower-potency serotonin–norepinephrine–dopamine releasing agent (SNDRA). The predicted log P of HMA is 0.6.
