MDMA

1-(1,3-benzodioxol-5-yl)-N-methylpropan-2-amine

Overview

MDMA belongs to Entactogens/Empathogens / Phenethylamines.

Key safety note: MDMA can cause life-threatening hyperthermia, especially with exertion in hot environments.^[6]^[4]

Effects

Subjective effects vary. What a substance feels like depends on dose, individual physiology, mindset, and setting. The points below describe commonly reported effects, not guaranteed, uniform, or desirable outcomes.

Emotional warmth
Empathy & closeness
Euphoria
Sociability
Well-being & acceptance
Sensory enhancement
Stimulation & energy
Urge to move / dance
Mild perceptual changes
Jaw clenching (bruxism)
Dilated pupils
Raised heart rate, BP & temperature
Sweating
Reduced appetite
Nausea
Comedown (low mood, fatigue)

Dosing & duration

Harm-reduction note: These are commonly cited reference ranges, not a recommendation or a “safe” dose. Potency, purity, body chemistry, tolerance, and drug combinations vary widely. Start low, go slow, wait for full effects before redosing, and never assume an unknown product matches these figures. Missing data is not evidence of safety.

Oral. These are commonly cited recreational reference ranges, not clinically established safe doses. Delayed onset, non-linear pharmacokinetics and accumulation make redosing hazardous. Heat, exertion, excessive water intake and drug combinations can increase risk. No fixed interval between uses has been established to prevent harm. Unregulated products may contain other drugs, and a negative screening test cannot establish safety.

Dose ranges

Threshold

20 mg

Light

20–80 mg

Common

80–120 mg

Strong

120–150 mg

Heavy

150 mg +

Duration

onset

30–45 min

peak

1.5–2.5 h

total

3–6 h

after effects

12–48 h

Chemical & Physical Properties

Formula	C11H15NO2
Molar mass	193.24 g/mol
State	Solid (usually the hydrochloride salt, crystalline, free base is a colourless oil)
Melting point	147–153 °C (hydrochloride salt)
Boiling point	100–110 °C at 0.4 mmHg (free base, under vacuum)
Density	Not reported
Vapor pressure	Not reported
pKa	9.9 (basic amine)
LogP	2.15 (exp, free base)
Solubility	Hydrochloride salt: slightly soluble in water, soluble in chloroform: the form the drug is normally encountered as (white crystalline powder), Free base: an oil, soluble in organic solvents (ethanol, chloroform, ether) and practically insoluble in water
Refractive index	Not reported

Identifiers & Synonyms

CAS	42542-10-9
CAS (enantiomer)
PubChem CID	1615
InChIKey	SHXWCVYOXRDMCX-UHFFFAOYSA-N
InChI	InChI=1S/C11H15NO2/c1-8(12-2)5-9-3-4-10-11(6-9)14-7-13-10/h3-4,6,8,12H,5,7H2,1-2H3
SMILES	CC(CC1=CC2=C(C=C1)OCO2)NC

Synonyms

3,4-methylenedioxymethamphetamine
Ecstasy
Midomafetamine
Adam
MDMA
Molly
Mandy
Pingers
XTC

Pharmacodynamics & Biochemistry

MDMA (3,4-methylenedioxymethamphetamine) is the prototypical entactogen ('empathogen'). Its core action is monoamine release: it is carried into the nerve terminal as a substrate by the serotonin (SERT), noradrenaline (NET) and dopamine (DAT) transporters, where it disrupts vesicular storage via VMAT2 and reverses transporter flow, so the transporters pump serotonin, noradrenaline and dopamine OUT into the synapse instead of clearing them. Functionally it is serotonin-preferring as a releaser: the large serotonin release, together with downstream oxytocin and prolactin release, drives the characteristic warmth, empathy and emotional openness, while the substantial noradrenaline and dopamine release produces the stimulant, euphoric and cardiovascular effects. In transfected human cells its transporter potency (uptake-inhibition IC50) is highest at the noradrenaline transporter (~0.45 µM), intermediate at the serotonin transporter (~1.4 µM) and weak at the dopamine transporter (~17 µM). Secondary actions include direct activity at serotonin receptors and TAAR1, with potency dependent on the receptor and assay. 5-HT2B agonism raises a potential concern about heart-valve effects with repeated exposure. Delayed low mood after use is reported, but cannot be attributed to serotonin depletion alone from these receptor findings. MDMA is metabolised by several hepatic CYP enzymes. CYP2D6 contributes strongly to O-demethylenation to HHMA, which can then be O-methylated to HMMA and conjugated. N-demethylation produces the active metabolite MDA, with contributions from enzymes including CYP2B6 and CYP1A2. MDMA also inhibits CYP2D6 and shows non-linear pharmacokinetics, so repeated or higher doses can cause disproportionate increases in exposure. Metabolism is stereoselective. MDMA is usually encountered as a racemate.

Biological targets

SERT
NET
DAT
VMAT2
5-HT2A

Binding & functional measurements

Target	Measurement	Species
5-HT2A receptor	Ki 7,800 ± 2,400 nM	Human
Dopamine transporter	EC50 7,500 ± 2,300 nM Emax 94 ± 10%	Human
Dopamine transporter	Ki 8,290 ± 1,670 nM	Human
Dopamine transporter	Ki 4,870 ± 650 nM	Mouse
Dopamine transporter	EC50 120 ± 8.0 nM Emax 101%	Rat
Noradrenaline transporter	EC50 360 ± 92 nM Emax 147 ± 15%	Human
Noradrenaline transporter	Ki 1,190 ± 130 nM	Human
Noradrenaline transporter	Ki 1,750 ± 510 nM	Mouse
Noradrenaline transporter	EC50 90 ± 13 nM Emax 99%	Rat
Serotonin transporter	EC50 1,100 ± 290 nM Emax 85.1 ± 7.8%	Human
Serotonin transporter	Ki 2,410 ± 730 nM	Human
Serotonin transporter	Ki 640 ± 50 nM	Mouse
Serotonin transporter	EC50 85 ± 16 nM Emax 104%	Rat
TAAR1	Ki 2,400 ± 1,100 nM	Mouse
TAAR1	Ki 370 ± 120 nM	Rat

Pharmacokinetics

Bioavailability	Not reported
T_max	text: ≈2 h. low: 2. high: 2. unit: h. approx: true
Half-life	text: 7–9 h. low: 7. high: 9. unit: h
V_d	Not reported
Protein binding	Not reported
Metabolism	Hepatic metabolism via several CYP enzymes. CYP2D6 contributes to O-demethylenation to HHMA, followed by methylation to HMMA and conjugation. N-demethylation yields active MDA. MDMA also inhibits CYP2D6.
Excretion	renal elimination of parent compound and metabolites

Toxicology & Safety

Harm-reduction note: Toxicity and risk depend on dose, route, purity, combinations, setting, and individual health factors. Missing harms should never be interpreted as evidence of safety.

97 mg/kg (rat, oral)

MDMA can cause life-threatening hyperthermia, especially with exertion in hot environments. Complications include muscle breakdown, kidney failure and clotting disturbances. Hyponatraemia can result from impaired water excretion and excessive fluid intake, so drinking large amounts of water is dangerous. MAOIs and some other serotonergic combinations can cause serotonin toxicity. Metabolic inhibitors, including ritonavir, can increase or otherwise alter exposure. MDMA raises heart rate and blood pressure. Low mood, anxiety and sleep disturbance may follow use and have multiple possible contributors. Animal studies demonstrate serotonergic neurotoxicity under some exposure conditions. Associations with cognitive and mood problems in people who use MDMA do not by themselves establish the extent of neuronal injury or separate MDMA's effects from other exposures. Repeated 5-HT2B activation raises concern about possible heart-valve effects. Unregulated products may contain other substances. Drug checking has limits, and no fixed interval between uses has been established to prevent these harms.^[6]^[4]

Legal Status

Legal note: Legal status can change over time and may vary by country, region, formulation, analogue status, prescription context, and enforcement practice. Always confirm with current official sources before relying on this section.

US: Schedule I. UK: Class A. DE: BtMG Anlage I

Interactions & Contraindications

Drug interactions

MAOIs Risk of severe, potentially fatal serotonin syndrome and hypertensive reactions, never combine.^[6]

Strong CYP2D6 inhibitors (e.g. paroxetine, fluoxetine) Can alter MDMA metabolism and increase exposure. The size and clinical consequences depend on the inhibitor, dose and other drugs. Reduced subjective effects do not imply lower toxicity.^[6]^[5]

SSRIs, SNRIs, Other serotonergic drugs, Tramadol, Triptans, Lithium Serotonin-syndrome risk. SSRIs also strongly blunt the desired effects by blocking SERT.^[6]

Stimulants (amphetamines, cocaine) Additive cardiovascular strain and hyperthermia, worse with exertion in heat.^[6]

Contraindications

Cardiovascular disease, hypertension or arrhythmia includes arrhythmia and a history of cardiac valve disease.^[6]

Concurrent MAOI, SSRI/SNRI or other serotonergic medication^[6]

Concurrent ritonavir or other strong CYP2D6 inhibitor^[6]

Personal or family history of psychosis, schizophrenia or bipolar disorder^[6]^[4]

Hot, dehydrating environments (overheating risk)^[4]^[6]

Kidney or liver impairment^[4]^[6]

Pregnancy or breastfeeding^[4]^[6]

Usage & Context

The archetypal recreational entactogen ('ecstasy', 'molly', 'mandy'), used for euphoria, empathy, closeness, sensory enhancement and energy: central to dance, festival and club culture since the 1980s.
MDMA-assisted treatment of PTSD remains investigational in the United States. The FDA's August 2024 Complete Response Letter raised concerns about safety-data reliability and evidence of effectiveness. Australia permits specially authorised psychiatrists to access unapproved MDMA products for PTSD under restricted conditions.
It has no approved general medical use and is a Schedule I / Class A / Anlage I controlled substance in most countries.

Sources & Evidence

Further Information

More in this subclass