MDMA (Ecstasy / Molly)
3,4-methylenedioxymethamphetamine
Can kill by overheating, low sodium, or serotonin syndrome.
Banned / Harmful evidence
☠️Banned & Harmful
Evidence tier
Banned / Harmful
Research weight
Not supported
Citations
19 verified / 19
Classification
Banned & Harmful
⊘
What the evidence says. Linked to serious harm and/or banned in sport and many jurisdictions. Listed for awareness and safety only — NOT a recommendation.
⚠
Health warning. MDMA can kill through overheating (hyperthermia), dangerously low blood sodium, and serotonin syndrome, and it damages serotonin neurons. Street pills are frequently adulterated with unknown, more dangerous substances.
What is MDMA (Ecstasy / Molly)?
MDMA (Ecstasy / Molly) (3,4-methylenedioxymethamphetamine) is a banned or harmful substance marketed for temporary euphoria, emotional closeness and energy — followed by a serotonin 'crash'. NutriDex grades the human evidence as Banned / Harmful. MDMA floods the brain with serotonin, producing short-lived euphoria — and several potentially fatal failure modes. The most common causes of ecstasy-related death are hyperthermia (overheating to organ failure), hyponatremia (dangerously low sodium from over-drinking water, causing seizures and brain swelling), and serotonin syndrome. Animal studies show lasting damage to serotonin neurons, and street 'ecstasy' is frequently cut with unknown adulterants. Listed as a warning only.
Marketed Claims (unproven)
✕Temporary euphoria, emotional closeness and energy — followed by a serotonin 'crash'
Dosing & Compounds
Use & Legality
No safe dose. Illegal; pills/powders are commonly adulterated with other, riskier drugs.
Active Compounds
Safety & Cautions
⚠ EXTREME HARM. Fatal overheating and rhabdomyolysis, life-threatening low sodium (seizures, brain swelling), serotonin syndrome, and lasting serotonin-system damage. Dangerous with antidepressants and other drugs. Adulterated supply makes every dose unpredictable. Illegal. Educational only — always check with your doctor or pharmacist before combining MDMA (Ecstasy / Molly) with any medicine.
Evidence & Risk Findings ★ 19 studies
systematic review and meta-analysis
Systematic review & meta-analysis of RCTs (Shahrour 2024, Neuropsychopharmacol Rep)
✓ Full text
Pooled RCTs found MDMA-assisted psychotherapy significantly reduced CAPS PTSD scores versus control, with 100-125 mg associated with a standardized mean difference of -0.86 (95% CI -1.23 to -0.50) at 4-12 weeks.
overview of systematic reviews
Overview of systematic reviews and meta-analyses (2025, PMC)
✓ Full text
Umbrella review of 14 systematic reviews (up to ~353 participants) found consistent efficacy of MDMA-assisted psychotherapy for PTSD but flagged small samples, expectancy/unblinding, and safety-data limitations.
systematic review and meta-analysis
Neurocognitive effects in abstinent users: systematic review & meta-analysis (Ung 2025, J Psychopharmacol)
✓ PubMed
Meta-analysis of 14 studies found both current and abstinent recreational MDMA users had poorer learning and memory than MDMA-naive controls, with no recovery seen after longer abstinence (low-quality evidence).
systematic review
MDMA-AT vs current options for treatment-resistant PTSD: systematic review (2025, PLOS One)
✓ Full text
Systematic literature review of chronic, treatment-resistant moderate-or-higher PTSD reported that 5 of 6 efficacy studies (83%) showed significantly greater PTSD symptom improvement with MDMA-assisted therapy versus placebo, while noting durability and comparative-evidence gaps.
systematic review
Alcohol as risk factor for MDMA hyperthermia: systematic review (2021)
✓ PubMed
Systematic review concluded concomitant alcohol use worsens MDMA-induced hyperthermia via impaired thermoregulation, dehydration and delayed sweating, increasing risk of fatal heat stroke.
regulatory action
FDA Complete Response Letter, MDMA for PTSD (NDA 215455, 2024)
✓ Source
On 8 Aug 2024 the FDA declined to approve Lykos Therapeutics' midomafetamine (MDMA)-assisted therapy for PTSD, citing unresolved efficacy durability, functional-unblinding/bias and safety-documentation concerns and requesting an additional adequate Phase 3 trial.
systematic review
MDMA cardiotoxicity: systematic review of experimental and autopsy data (2019, Cardiovasc Toxicol)
✓ PubMed
Systematic review of human, animal, autopsy and case data concluded MDMA can cause rhythm disturbances, myocardial injury, cardiomyopathy and sudden cardiac death, including a fatal case of acute cardiotoxicity in an adolescent.
Meta-analysis
Roberts et al. 2016 (Psychol Med)
✓ PubMed
Meta-analysis of 39 studies (1221 ecstasy users vs 1242 polydrug controls) found overall executive dysfunction in ecstasy users (SMD = -0.18, 95% CI -0.26 to -0.11), with significant deficits in access to long-term memory (SMD = -0.33), updating (SMD = -0.26) and switching (SMD = -0.19); inhibitory control was unaffected.
Meta-analysis
Laws & Kokkalis 2007 (Hum Psychopharmacol)
✓ PubMed
Meta-analysis of 26 studies showed ecstasy users have moderate-to-large memory impairments vs non-users: short-term memory d = -0.63, long-term memory d = -0.87, and verbal memory d = -1.00 (large); visual memory was less affected (d = -0.27, partly attributable to cannabis co-use).
randomized controlled trial
Phase 3 RCT MAPP2 (Mitchell 2023, Nat Med)
✓ Full text
In 104 patients with moderate-to-severe PTSD, MDMA-assisted therapy lowered CAPS-5 scores significantly more than placebo with therapy (LS mean difference -23.7; p<0.001).
RCT
Mitchell 2023 (MAPP2)
✓ Source
In the confirmatory phase 3 MAPP2 trial (n=104, moderate-to-severe PTSD), MDMA-assisted therapy reduced CAPS-5 severity more than placebo with therapy (treatment effect Cohen's d=0.7, P<0.001); 71% of MDMA participants no longer met PTSD criteria vs 48% with placebo.
randomized controlled trial
Phase 3 RCT MAPP1 (Mitchell 2021, Nat Med)
✓ Full text
In 90 patients with severe PTSD, MDMA-assisted therapy reduced CAPS-5 severity significantly more than placebo with therapy over 18 weeks (p<0.0001; large effect, d~0.9).
Safety / toxicology
MDMA hepatic failure 2024
✓ Full text
Case report of a 22-year-old who developed seizures, hyperthermia (43C), rhabdomyolysis (CK >360,000 U/L), acute kidney injury, DIC and fulminant hepatic failure after acute MDMA ingestion, requiring emergency liver transplantation.
case report and literature review
MDMA-induced hyponatremia: case report & literature review (2021)
✓ PubMed
Case report and review describing life-threatening MDMA-induced hyponatremia and cerebral edema, with higher incidence and severity in women, treatable with hypertonic saline.
Safety / toxicology
Toxicology (StatPearls)
✓ Full text
Leading causes of death: hyperthermia, serotonin syndrome and hyponatremia.
Review
Davies et al. 2018 (Br J Nurs)
✓ PubMed
Review documenting a recent resurgence in MDMA popularity with an associated rise in deaths; details the pathophysiology of life-threatening toxicity (serotonin syndrome, hyperthermia, cardiac arrest) and acute/critical-care management including ECMO.
Review
Hall & Henry 2006 (Br J Anaesth)
✓ PubMed
Authoritative clinical review of acute MDMA toxicity describing life-threatening harms including hyperpyrexia/hyperthermia, multi-organ failure, rhabdomyolysis, hyponatremia (from excess water intake/SIADH) and sudden death; establishes the clinical management framework for acute presentations.
Study
Adulteration
✓ Full text
Street pills/powder frequently contain other, more dangerous drugs.
Preclinical
Neurotoxicity studies
✓ PubMed
Loss of serotonin-axon markers in primates; deficits in memory and mood.