Entactogen

Entactogens, also known as empathogens or connectogens, are a class of psychoactive drugs that induce the production of experiences of emotional communion, oneness, connectedness, emotional openness—that is, empathy—as particularly observed and reported for experiences with MDMA.<ref name="Nichols2022" /><ref name="StockerLiechti2024" /><ref name="Oeri2021" /><ref name="NicholsYensenMetzner1993" /><ref name="Nichols1986" /> This class of drug is distinguished from the classes of hallucinogens or psychedelics and stimulants, although entactogens, for instance MDMA, can also have these properties.<ref name="Nichols2022" /><ref name="Nichols1986" /><ref name="NicholsHoffmanOberlender1986">Template:Cite journal</ref><ref name="McGregorThompsonCallaghan2010">Template:Cite book</ref> Entactogens are used both as recreational drugs<ref name="HillThomas2011" /> and are being investigated for medical use in the treatment of psychiatric disorders, for instance MDMA-assisted therapy for post-traumatic stress disorder (PTSD).<ref name="Baldo2024" /><ref name="Singh2025" /><ref name="WolfgangFonzoGray2025" />

Notable members of this class include MDMA, MDA, MDEA, MDOH, MBDB, 5-APB, 5-MAPB, 6-APB, 6-MAPB, methylone, mephedrone, αMT, αET, and MDAI, among others.<ref name="Nichols2022" /><ref name="Oeri2021" /> Most entactogens are phenethylamines and amphetamines, although several, such as αMT and αET, are tryptamines.<ref name="Nichols2022" /><ref name="Oeri2021" /> When referring to MDMA and its counterparts, the term MDxx is often used (with the exception of certain non-entactogen drugs like MDPV).

Entactogens act as serotonin releasing agents (SRAs) as their key action.<ref name="Kamilar-BrittBedi2015" /><ref name="HalberstadtNichols2020" /><ref name="Oeri2021" /><ref name="Baggott2023" /><ref name="Baggott2024" /> However, entactogens also frequently have additional actions, such as induction of dopamine and norepinephrine and serotonin 5-HT₂ receptor agonism, which contributes to their effects as well.<ref name="Kamilar-BrittBedi2015" /><ref name="HalberstadtNichols2020" /><ref name="Oeri2021" /><ref name="Baggott2023" /><ref name="Baggott2024" /> It is thought that dopamine and norepinephrine release provide additional stimulant, euphoriant, and cardiovascular or sympathomimetic effects, serotonin 5-HT_2A receptor agonism produces psychedelic effects of variable intensity, and both dopamine release and serotonin 5-HT₂ receptor agonism may enhance the entactogenic effects and be critically involved in allowing for the qualitative "magic" of these drugs.<ref name="Kamilar-BrittBedi2015" /><ref name="HalberstadtNichols2020" /><ref name="Oeri2021" /><ref name="Baggott2023" /><ref name="Baggott2024" /> Entactogens that simultaneously induce serotonin and dopamine release, for instance MDMA, are known to produce long-lasting serotonergic neurotoxicity<ref name="BaggottMendelson2001">Template:Cite book</ref><ref name="SpragueEvermanNichols1998">Template:Cite journal</ref><ref name="Oeri2021" /> with associated cognitive and memory deficits as well as psychiatric changes.<ref name="Parrott2002">Template:Cite journal</ref><ref name="Parrott2013">Template:Cite journal</ref><ref name="AguilarGarcía-PardoParrott2020">Template:Cite journal</ref><ref name="MontgomeryRoberts2022">Template:Cite journal</ref>

MDA and MDMA were both first synthesized independently in the early 1910s.<ref name="Passie2023" /> The psychoactive effects of MDA were discovered in 1930 but were not described until the 1950s, MDA and MDMA emerged as recreational drugs in the 1960s, and the unique entactogenic effects of MDMA were first described in the 1970s.<ref name="Passie2023">Template:Cite book</ref><ref name="Bernschneider-ReifOxlerFreudenmann2006">Template:Cite journal</ref><ref name="BenzenhöferPassie2010">Template:Cite journal</ref><ref name="Alles1959a">Template:Cite book</ref><ref name="Alles1959b">Template:Cite book</ref> Entactogens as a unique pharmacological class depending on induction of serotonin release was established in the mid-1980s and novel entactogens such as MBDB were developed at this time and after.<ref name="Nichols2022" /><ref name="Nichols1986" /><ref name="NicholsHoffmanOberlender1986" /> Gordon Alles discovered the psychoactive effects of MDA,<ref name="Alles1959a" /><ref name="Alles1959b" /> Alexander Shulgin played a key role in bringing awareness to MDMA and its unique effects,<ref name="BenzenhöferPassie2010" /> and Ralph Metzner<ref name="Eisner1989">Template:Cite book</ref><ref name="MetznerAdamson2001">Template:Cite book</ref><ref name="Metzner1983">Template:Cite conference</ref> and David E. Nichols formally defined entactogens and established them as a distinct class of drugs.<ref name="Nichols2022" /><ref name="Nichols1986" /><ref name="NicholsHoffmanOberlender1986" /> Many entactogens like MDMA are controlled substances throughout the world.<ref name="Shulgin1992">Template:Cite book</ref><ref name="ShulginManningDaley2011">Template:Cite book</ref>

Uses

Recreational

Entactogens are used as recreational drugs, including notably at raves.<ref name="HillThomas2011">Template:Cite journal</ref>

Medical

Psychiatrists began using entactogens as psychotherapy tools in the 1970s despite the lack of clinical trials.<ref>Template:Cite book</ref> In recent years, the scientific community has been revisiting the possible therapeutic uses of entactogens. Therapeutic models using MDMA have been studied because of its entactogenic properties.<ref name=":1">Template:Cite book</ref> This type of therapy would be applicable for treating a patient who was experiencing psychological trauma such as PTSD. Traumatic memories can be linked to fear in the patients which makes engaging with these memories difficult. Administration of an entactogen such as MDMA allows the patient to disconnect from the fear associated with the traumatic memories and engage in therapy.<ref name=":1" /> MDMA acts by targeting the body's stress response in order to cause this therapeutic effect. In addition to reducing anxiety and a conditioned fear response, MDMA also reduces the avoidance of feelings.<ref name=":1" /> Patients are then able to trust themselves and their therapist and engage with traumatic memories under the influence of MDMA.

Although the therapeutic effects of entactogens may be promising, drugs such as MDMA have the potential for negative effects that are counter productive in a therapy setting. For example, MDMA may make negative cognition worse. This means that a positive experience is not a guarantee and can be contingent on aspects like the setting and the patient's expectations.<ref name=":2">Template:Cite journal</ref> Additionally there is no clear model of the psychopharmacological means for a positive or negative experience.<ref name=":2" /> There is also a potential concern for the neurotoxic effects of MDMA on the fiber density of serotonin neurons in the neocortex. High doses of MDMA may cause potential depletion of serotonergic axons. The same effects may not be caused by lower doses of MDMA required for treatment, however.<ref>Template:Cite book</ref>

MDMA-assisted psychotherapy (MDMA-AT) is in late-stage clinical trials to treat PTSD as of 2025.<ref name="Baldo2024">Template:Cite journal</ref><ref name="Singh2025">Template:Cite journal</ref><ref name="WolfgangFonzoGray2025">Template:Cite journal</ref>

Effects

Both terms adopted and used in naming the class of therapeutic drugs for MDMA and related compounds were chosen with the intention of providing some reflection of the reported psychological effects associated with drugs in the classification and distinguishing these compounds from classical psychedelic drugs such as LSD, mescaline, and psilocybin and major stimulants, such as methamphetamine and amphetamine.<ref name="NicholsYensenMetzner1993" /> Chemically, MDMA is classified as a substituted amphetamine (which includes stimulants like dextroamphetamine and psychedelics like 2,5-dimethoxy-4-methylamphetamine), which makes MDMA a substituted phenethylamine (which includes other stimulants like methylphenidate and other psychedelics like mescaline) by the definition of amphetamine. While chemically related both to psychedelics and stimulants, the psychological effects experienced with MDMA were reported to provide obvious and striking aspects of personal relatedness, feelings of connectedness, communion with others, and ability to feel what others feel—in short an empathic resonance is consistently evoked.<ref>Template:Cite journal</ref> While psychedelics like LSD may sometimes yield effects of empathic resonance, these effects tend to be momentary and likely passed over on the way to some other dimension or interest. In contrast, the main characteristic that distinguishes MDMA from LSD-type experiences is the consistency of the effects of emotional communion, relatedness, emotional openness—in short, empathy and sympathy.<ref name="NicholsYensenMetzner1993" />

Side effects

Side effects of entactogens like MDMA include mydriasis, nystagmus, jaw clenching, bruxism, insomnia, appetite loss, tachycardia, hypertension, and hyperthermia, among others.<ref name="Oeri2021" /><ref name="Baldo2024" /> Severe adverse effects of entactogens like MDMA can include dehydration, hyperthermia, seizures, rhabdomyolysis, disseminated intravascular coagulation, hyponatremia, acute renal failure, liver injury, serotonin syndrome, and valvular heart disease.<ref name="Baldo2024" /><ref name="LuethiLiechti2020" /> Entactogens can produce long-lasting serotonergic neurotoxicity<ref name="BaggottMendelson2001">Template:Cite book</ref><ref name="SpragueEvermanNichols1998">Template:Cite journal</ref><ref name="Oeri2021" /> and associated cognitive and memory deficits as well as psychiatric changes.<ref name="Parrott2002">Template:Cite journal</ref><ref name="Parrott2013">Template:Cite journal</ref><ref name="AguilarGarcía-PardoParrott2020">Template:Cite journal</ref><ref name="MontgomeryRoberts2022">Template:Cite journal</ref>

Overdose

Entactogens like MDMA show a much narrower margin of safety and greater toxicity in overdose than serotonergic psychedelics.<ref name="Henríquez-HernándezRojas-HernándezQuintana-Hernández2023">Template:Cite journal</ref> Whereas LSD and psilocybin have extrapolated human lethal doses relative to typical recreational doses of approximately 1,000-fold and 200-fold, respectively,<ref name="Thomas2024">Template:Cite book</ref> a reasonable estimated fatal dose of MDMA is only about 15 or 16Template:Nbsptimes a single typical recreational dose.<ref name="Henríquez-HernándezRojas-HernándezQuintana-Hernández2023" />

Interactions

Entactogens like MDMA pose high risks of severe and potentially fatal serotonin syndrome and hypertensive crisis in people on monoamine oxidase inhibitors (MAOIs) due to synergistic elevations of monoamines like serotonin and norepinephrine.<ref name="MalcolmThomas2022">Template:Cite journal</ref><ref name="EdinoffSwinfordOdisho2022">Template:Cite journal</ref> MDMA also has the potential to interact with various other drugs.<ref name="PapaseitPérez-MañáTorrens2020">Template:Cite journal</ref><ref name="SarparastThomasMalcolm2022">Template:Cite journal</ref><ref name="MohamedBenHamidaCassel2011">Template:Cite journal</ref>

Pharmacology

Mechanism of action

Entactogens like MDMA are serotonin releasing agents and hence are indirect agonists of serotonin receptors.<ref name="DunlapAndrewsOlson2018">Template:Cite journal</ref><ref name="Martinez-PriceKrebs-ThomsonGeyer2002" /><ref name="StoveDeLetterPiette2010" /> They produce entactogenic effects in animals such as increased prosocial behavior like adjacent lying, enhanced empathy-like behavior, and antiaggressive effects.<ref name="DunlapAndrewsOlson2018" /><ref name="ReinRaymondBoustani2024" /><ref name="Kamilar-BrittBedi2015">Template:Cite journal</ref> Likewise, MDMA increases sociability, prosociality, and emotional empathy in humans.<ref name="Kamilar-BrittBedi2015" />

In animals, MDMA induced prosocial behavior and elevations in circulating oxytocin levels and these effects were abolished by pretreatment with the serotonin 5-HT_1A receptor antagonist WAY-100635.<ref name="DunlapAndrewsOlson2018" /><ref name="Blanco-GandíaMateos-GarcíaGarcía-Pardo2015">Template:Cite journal</ref><ref name="ThompsonCallaghanHunt2007">Template:Cite journal</ref><ref name="EsakiSasakiNishitani2023">Template:Cite journal</ref><ref name="MorleyArnoldMcGregor2005">Template:Cite journal</ref> Conversely, the serotonin 5-HT_1A receptor agonist 8-OH-DPAT produced prosocial behavior and increased oxytocin levels similarly to MDMA.<ref name="DunlapAndrewsOlson2018" /><ref name="ThompsonCallaghanHunt2007" /><ref name="TanMartinBowen2020">Template:Cite journal</ref> In addition, MDMA has been shown to activate oxytocinergic neurons in the hypothalamus and this too is reversed by serotonin 5-HT_1A receptor antagonism.<ref name="DunlapAndrewsOlson2018" /><ref name="ThompsonCallaghanHunt2007" /><ref name="HuntMcGregorCornish2011">Template:Cite journal</ref> Subsequent research found that direct injection of the serotonin 5-HT_1A receptor WAY-100635 locally into the basolateral amygdala (BLA) suppressed MDMA-induced prosocial behavior and that direct injection of MDMA locally into the BLA significantly increased sociability.<ref name="HeifetsOlson2024">Template:Cite journal</ref><ref name="EsakiSasakiNishitani2023" />

The serotonin 5-HT_2B and 5-HT_2C receptor antagonist SB-206553 has also been found to block MDMA-induced prosocial behavior, although it produced potentially confounding thigmotaxis (hyperactivity at periphery of testing chamber) as well.<ref name="Blanco-GandíaMateos-GarcíaGarcía-Pardo2015" /><ref name="MorleyArnoldMcGregor2005" /> Conversely, the serotonin 5-HT_1B receptor antagonist GR-55562 and the serotonin 5-HT_2A receptor antagonist ketanserin were both ineffective.<ref name="Blanco-GandíaMateos-GarcíaGarcía-Pardo2015" /><ref name="EsakiSasakiNishitani2023" /><ref name="MorleyArnoldMcGregor2005" /> Likewise, another study found that selective antagonists of the serotonin 5-HT_1B, 5-HT_2A, 5-HT_2C, and 5-HT₄ receptors (SB-216641), volinanserin (MDL-100907), SB-242084, and SB-204070, respectively) were all ineffective in suppressing MDMA-induced prosocial activity.<ref name="HeifetsOlson2024" /><ref name="EsakiSasakiNishitani2023" /> Other research has found that serotonin 5-HT_2B receptor inactivation abolishes the serotonin release induced by MDMA and attenuates many of its effects.<ref name="Martinez-PriceKrebs-ThomsonGeyer2002">Template:Cite journal</ref><ref name="StoveDeLetterPiette2010">Template:Cite journal</ref><ref name="DolyValjentSetola2008">Template:Cite journal</ref> In addition to the preceding findings, induction of serotonin release by MDMA in the nucleus accumbens and consequent activation of serotonin 5-HT_1B receptors in this area is implicated in its enhancement of prosocial behaviors, whereas consequent activation of yet-to-be-determined serotonin receptors in this area is implicated in its enhancement of empathy-like behaviors.<ref name="Nichols2022">Template:Cite journal</ref><ref name="ReinRaymondBoustani2024">Template:Cite journal</ref><ref name="HeifetsSalgadoTaylor2019">Template:Cite journal</ref><ref name="WalshLlorachCardozoPinto2021">Template:Cite journal</ref> Injection of the serotonin 5-HT_1B receptor antagonist NAS-181 directly into the nucleus accumbens blocked the prosocial behaviors of MDMA.<ref name="HeifetsSalgadoTaylor2019" />

On the basis of the serotonin 5-HT_1A receptor-mediated oxytocin release with MDMA, it has been proposed that increased oxytocinergic signaling may mediate the prosocial effects of MDMA in animals.<ref name="DunlapAndrewsOlson2018" /><ref name="ThompsonCallaghanHunt2007" /> Accordingly, intracerebroventricular injection of the peptide oxytocin receptor antagonist tocinoic acid blocked MDMA- and 8-OH-DPAT-induced prosocial effects.<ref name="DunlapAndrewsOlson2018" /><ref name="ThompsonCallaghanHunt2007" /><ref name="Wronikowska-DenysiukMrozekBudzyńska2023" /> However, in a subsequent study, systemically administered C25, a non-peptide oxytocin receptor antagonist, failed to affect MDMA-induced prosocial behavior, whereas the vasopressin V_1A receptor antagonist relcovaptan (SR-49059) was able to block MDMA-induced prosocial activity.<ref name="DunlapAndrewsOlson2018" /><ref name="Wronikowska-DenysiukMrozekBudzyńska2023" /> It might be that tocinoic acid is non-selective and also blocks the vasopressin V_1A receptor or that C25 is peripherally selective and is unable to block oxytocin receptors in the brain.<ref name="DunlapAndrewsOlson2018" /><ref name="Wronikowska-DenysiukMrozekBudzyńska2023" /> More research is needed to clarify this.<ref name="Wronikowska-DenysiukMrozekBudzyńska2023" /><ref name="DunlapAndrewsOlson2018" /> In any case, in another study, the non-peptide and centrally active selective oxytocin receptor antagonist L-368899 abolished MDMA-induced prosocial behavior.<ref name="Wronikowska-DenysiukMrozekBudzyńska2023">Template:Cite journal</ref><ref name="Kuteykin-TeplyakovMaldonado2014">Template:Cite journal</ref> Conversely, in other studies, different oxytocin receptor antagonists were ineffective.<ref name="HeifetsSalgadoTaylor2019" />

As in animals, MDMA greatly increases circulating oxytocin levels in humans.<ref name="DunlapAndrewsOlson2018" /> Serotonin reuptake inhibitors and norepinephrine reuptake inhibitors reduced the subjective effects of MDMA in humans, for instance increased extroversion, self-confidence, closeness, openness, and talkativeness.<ref name="Kamilar-BrittBedi2015" /> The 5-HT_2A receptor antagonist ketanserin reduced MDMA-induced increases in friendliness.<ref name="Kamilar-BrittBedi2015" /> MDMA-induced emotional empathy was not affected by the serotonin 5-HT_1A receptor antagonist pindolol or by intranasal oxytocin.<ref name="KuypersdelaTorreFarre2014">Template:Cite journal</ref> Similarly, MDMA-induced emotional empathy and prosocial behavior have not been associated with circulating oxytocin levels.<ref name="KuypersdelaTorreFarre2014" /><ref name="DunlapAndrewsOlson2018" /> As such, the role of oxytocin in the entactogenic effects of MDMA in humans is controversial.<ref name="DunlapAndrewsOlson2018" />

Other serotonin releasing agents, like fenfluramine, show prosocial effects in animals similar to those of MDMA.<ref name="BeheraJogaYerram2024">Template:Cite journal</ref><ref name="HeifetsSalgadoTaylor2019" /> Fenfluramine has likewise been reported to improve social deficits in children with autism.<ref name="HeifetsSalgadoTaylor2019" /><ref name="AmanKern1989">Template:Cite journal</ref> Selective agonists of the serotonin 5-HT_1A and 5-HT_1B receptors and of the oxytocin receptors have been or are being investigated for the potential treatment of social deficits and aggression.<ref name="deBoerKoolhaas2005">Template:Cite journal</ref><ref name="Olivier2004">Template:Cite journal</ref><ref name="FelthousMcCoyNassif2021">Template:Cite journal</ref><ref name="SałaciakPytka2021">Template:Cite journal</ref> Examples include batoprazine, eltoprazine (DU-28853), fluprazine (DU-27716), F-15,599 (NLX-01), zolmitriptan (ML-004), and LIT-001.<ref name="FelthousMcCoyNassif2021" /><ref name="SałaciakPytka2021" /><ref name="NasharWhitfieldMikusek2022">Template:Cite book</ref> Serotonergic psychedelics, for instance lysergic acid diethylamide (LSD) and psilocybin, which act as non-selective serotonin receptor agonists including of the serotonin 5-HT₁ and 5-HT₂ receptors, have shown prosocial and empathy-enhancing effects in animals and/or humans as well, both acutely and long-term.<ref name="MarkopoulosInserraDeGregorio2021">Template:Cite journal</ref><ref name="BhattWeissman2024">Template:Cite journal</ref><ref name="KupferbergHasler2024">Template:Cite journal</ref>

The serotonin release of MDMA appears to be the key pharmacological action mediating the entactogenic, prosocial, and empathy-enhancing effects of the drug.<ref name="Kamilar-BrittBedi2015" /><ref name="HalberstadtNichols2020">Template:Cite book</ref><ref name="Oeri2021">Template:Cite journal</ref> However, in addition to serotonin release, MDMA is also a potent releasing agent of norepinephrine and dopamine, and hence acts as a well-balanced serotonin–norepinephrine–dopamine releasing agent.<ref name="HalberstadtNichols2020" /><ref name="Oeri2021" /> Additionally, MDMA is a direct agonist of several serotonin receptors, including of the serotonin 5-HT₂ receptors, with moderate affinity.<ref name="HalberstadtNichols2020" /><ref name="Oeri2021" /> These actions are thought to play an important role in the effects of MDMA, including in its psychostimulant, euphoriant, and mild psychedelic effects, as well as in its unique and difficult-to-replicate "magic".<ref name="HalberstadtNichols2020" /><ref name="Baggott2023">Template:Cite conference</ref><ref name="Oeri2021" /><ref name="HealGosdenSmith2023">Template:Cite journal</ref> It has been said by Matthew Baggott that few to no MDMA analogues, including MBDB, methylone, 6-APDB, 5-APDB, 6-APB, 5-APB, MDAT, and MDAI among others, reproduce the full quality and "magic" of MDMA.<ref name="Baggott2023" /><ref name="Baggott2024">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Exceptions may anecdotally include 5-MAPB, particularly in specific enantiomer ratios, and the Borax combo.<ref name="Baggott2023" /><ref name="Baggott2024" /><ref name="US11767305B2">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> The unique properties of MDMA are believed to be dependent on a very specific mixture and ratio of pharmacological activities, including combined serotonin, norepinephrine, and dopamine release and direct serotonin receptor agonism.<ref name="Baggott2023" /><ref name="Baggott2024" />

Ariadne, the α-ethyl analogue of the serotonergic psychedelic DOM, fully substitutes for MDMA in rodent drug discrimination tests, suggesting that it may have entactogen-like effects.<ref name="CunninghamBockSerrano2023">Template:Cite journal</ref><ref name="Glennon1993">Template:Cite journal</ref> This property is unusual among psychedelics, and is in notable contrast to DOM, which at best partially substitutes for MDMA.<ref name="Glennon1993" /> Unlike conventional entactogens, Ariadne shows no activity at the monoamine transporters, and instead acts as a selective serotonin 5-HT₂ receptor partial agonist, including as a lower-efficacy agonist of the serotonin 5-HT_2A receptor.<ref name="CunninghamBockSerrano2023" /> Certain other psychedelics and related compounds, like low doses of 2C-B, are also selective serotonin 5-HT₂ receptor partial agonists that have likewise been implicated as having entactogenic effects.<ref name="LuethiLiechti2020">Template:Cite journal</ref><ref name="WillsErickson2012">Template:Cite book</ref><ref name="GonzálezTorrensFarré2015">Template:Cite journal</ref> MDMA itself is notable in being a lower-efficacy partial agonist of the serotonin 5-HT_2A receptor as well.<ref name="PittsCurryHampshire2018">Template:Cite journal</ref><ref name="KolaczynskaDucretTrachsel2022">Template:Cite journal</ref> The stimulus effects of MDMA in the drug discrimination paradigm are partially blocked by the selective serotonin 5-HT_2A receptor antagonist volinanserin in rodents.<ref name="Baker2018">Template:Cite journal</ref> Similarly, the psychoactive effects of MDMA are partially blocked by the relatively selective serotonin 5-HT_2A receptor antagonist ketanserin in humans.<ref name="HalberstadtNichols2020" /><ref name="LiechtiSaurGamma2000">Template:Cite journal</ref><ref name="LiechtiVollenweider2001">Template:Cite journal</ref><ref name="vanWelKuypersTheunissen2012">Template:Cite journal</ref>

History

The history of MDMA and other entactogens has been reviewed.<ref name="Passie2023" /><ref name="Bernschneider-ReifOxlerFreudenmann2006" /><ref name="Shulgin1990">Template:Cite book</ref><ref name="BenzenhöferPassie2010" /><ref name="Pentney2001">Template:Cite journal</ref><ref name="Nichols2022" />

Society and culture

Etymology

The term empathogen, meaning "generating a state of empathy", was independently coined by Ralph Metzner in 1983 and David E. Nichols in 1984 as a term to denote a class of drugs that includes MDMA and other agents with similar effects.<ref name="Eisner1989" /><ref name="MetznerAdamson2001" /><ref name="Metzner1983" /> Subsequently, in 1986, Nichols rejected this initial terminology and adopted, instead, the term entactogen, meaning "producing a touching within", to denote this class of drugs, asserting a concern with the potential for improper association of the term empathogen with negative connotations related to the Greek root πάθος páthos ("suffering; passion").<ref name="Nichols2022" /><ref name="Nichols1986">Template:Cite journal</ref><ref name="NicholsHoffmanOberlender1986" /> Additionally, Nichols wanted to avoid any association with the term pathogenesis.<ref name="Colman2015">Template:Cite book</ref>

Nichols also thought the original term was limiting, and did not cover other therapeutic uses for the drugs that go beyond instilling feelings of empathy.<ref name="NicholsYensenMetzner1993" /> The hybrid word entactogen is derived from the roots en (Template:Langx), tactus (Template:Langx) and -gen (Template:Langx).<ref name="Nichols1986" /> Entactogen is not becoming dominant in usage, and, despite their difference in connotation, they are essentially interchangeable, as they refer to precisely the same chemicals.

In 2024, an additional alternative term, connectogen, was proposed and introduced by Kurt Stocker and Matthias Liechti.<ref name="StockerLiechti2024">Template:Cite journal</ref>

List of entactogens

The chemicals below have a varying degree of entactogenic effects; some of them induce additional effects, including serenic effects, stimulant effects, antidepressant effects, anxiolytic effects, and psychedelic effects.<ref name="Colman2015" />

Phenethylamines

• 2C-B<ref name="LuethiLiechti2020" /><ref name="WillsErickson2012" /><ref name="GonzálezTorrensFarré2015" />
• 2C-T-2Template:Citation needed
• 2C-T-7Template:Citation needed
• MetaescalineTemplate:Citation needed

Amphetamines

• 3-ChloromethamphetamineTemplate:Citation needed
• 3-MethoxymethamphetamineTemplate:Citation needed
• 4-Fluoroamphetamine (4-FA)Template:Citation needed
• para-Methoxyamphetamine (PMA)
• 4-Methylthioamphetamine (4-MTA)

Methylenedioxyamphetamines (benzodioxoles)

• MMDA (5-methoxy-MDA)
• 5-Methyl-MDA
• Methylbenzodioxolylbutanamine (MBDB)
• Methylenedioxyamphetamine (MDA)
• Methylenedioxyethylamphetamine (MDEA)
• Methylenedioxymethamphetamine (MDMA)
• Methylenedioxyhydroxyamphetamine (MDOH)
• Lys-MDA
• Lys-MDMA

Benzofurans

• 6-(2-Aminopropyl)benzofuran (6-APB) (benzofury)
• 5-(2-Aminopropyl)benzofuran (5-APB)
• 5-(2-Methylaminopropyl)benzofuran (5-MAPB)

Others

• 5-APDI (indanylaminopropane; IAP)
• Methamnetamine (PAL-1046)
• SeDMA
• ODMA
• TDMA

Cathinones

• Mephedrone (4-MMC)
• 3-Methylmethcathinone (3-MMC, metaphedrone)
• Methylone (MDMC; βk-MDMA)
• Butylone (βk-MBDB)
• Flephedrone (4-FMC)Template:Citation needed
• TH-PVPTemplate:Citation needed

Aminorexes

• 4,4'-Dimethylaminorex (4,4'-DMAR)Template:Citation needed
• Methylenedioxy-4-methylaminorex (MDMAR)Template:Citation needed

Tryptamines

α-Alkyltryptamines

• α-Ethyltryptamine (αET)
• α-Methyltryptamine (αMT)
• BK-NM-AMT
• BK-5F-NM-AMT

2-Aminoindanes

• 5-Iodo-2-aminoindane (5-IAI)
• 5,6-Methylenedioxy-2-aminoindane (MDAI)
• 5,6-Methylenedioxy-N-methyl-2-aminoindane (MDMAI)
• 5-Methoxy-6-methyl-2-aminoindane (MMAI)
• 5-Methoxy-2-aminoindane (MEAI, 5-MeO-AI)

Indolizines

• 1Z2MAP1O

External links

• Template:Commonscat-inline
• Entactogens - Massviews Analysis - Wikipedia

{{#invoke:Navbox|navbox}} Template:Monoamine releasing agents Template:Major Drug Groups Template:Chemical classes of psychoactive drugs