The terms empathogen and entactogen are different terms used to describe a class of psychoactive drugs that produce distinctive emotional and social effects similar to MDMA ("ecstasy"). Other members of this class are MDA, MDEA, MBDB, BDB and AET. When referring to MDMA and related analogs the term 'MDxx' is often used, the exception being MDPV which is purely a stimulant. Entactogens are often incorrectly referred to as hallucinogens or stimulants. The chemical structure of most entactogens contains a substituted amphetamine core.
"Entactogen" was coined by David E. Nichols as an alternative to "empathogen", attempting to avoid the potential for improper association of the latter with negative concepts related to the Greek root "pathos" (sympathy); Nichols also thought the word was limiting, and did not cover other therapeutic uses for the drugs which go beyond instilling feelings of empathy. The word "entactogen" is derived from the roots "en" (Greek: within), "tactus" (Latin: touch) and "gen" (Greek: produce). Neither term is dominant in usage, and despite their difference in connotation are essentially interchangeable as they refer to precisely the same chemicals.
These drugs appear to produce a different spectrum of psychological effects from stimulants such as methamphetamine and amphetamine or from psychedelic drugs such as LSD or Psilocybin. As implied by the category names, users of entactogens say the drugs often produce feelings of empathy, love, and emotional closeness to others. However, there have been only very preliminary comparisons of these different drugs in humans in properly controlled laboratory studies.
If MDMA is taken as a representative entactogen, the pharmacological mechanisms of this class appear to resemble those of methamphetamine. Extracellular dopamine, serotonin, and norepinephrine are all increased by both MDMA and methamphetamine. However, MDMA tends to release greater amounts of serotonin proportionately compared to methamphetamine, which might account for its different effects. It has also been noted anecdotally that the combination of IAP, a primarily serotonin releasing amphetamine, and amphetamine, a primarily norepinephrine and dopamine releasing amphetamine, is remarkably similar in psychopharmaceutical effect to MDA. Entactogens other than MDMA have received relatively little scientific attention, making it difficult to draw conclusions about the mechanisms of entactogens in general.
- Nichols, D.E., Hoffman, A.J., Oberlender, R.A., Jacob P 3rd & Shulgin A.T. Derivatives of 1-(1,3-benzodioxol-5-yl)-2-butanamine: representatives of a novel therapeutic class 1986 J Med Chem 29 2009-15
- Nichols, D.E. Differences between the mechanism of action of MDMA, MBDB, and the classic hallucinogens. Identification of a new therapeutic class: entactogens 1986 J Psychoactive Drugs 18 305-13
- Nichols 1986: Abstract and full text online
- The Great Entactogen - Empathogen Debate from MAPS newsletter