High riskPsychoactive substance

MDMA (Ecstasy, Molly)

MDMA is a stimulant and empathogen that increases serotonin, dopamine, and noradrenaline. It may have important interactions with protease inhibitors and some integrase inhibitors, increasing the risk of hyperthermia and cardiovascular toxicity.

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What is it?

MDMA (3,4-methylenedioxymethamphetamine), known as ecstasy or molly, is a substance with stimulant and empathogenic effects. It works by increasing the release of serotonin, dopamine, and noradrenaline in the brain, leading to intense feelings of euphoria, empathy, and emotional connection. It is mainly metabolised by the enzyme CYP2D6.

How is it used?

  • Pills or tablets (most common in party settings)
  • Powder or crystals (which may be snorted or dissolved)
  • Capsules
  • Liquid form (less common)

Purity and composition of street products vary a lot. Drug checking kits may help confirm the presence of MDMA before use.

How does it work?

MDMA causes a strong release of neurotransmitters that may produce:

  • Intense euphoria and well-being
  • Empathy and emotional connection with others
  • Increased energy and physical endurance
  • Greater sensory perception (touch, music, light)
  • A post-use comedown once effects fade

Effects usually begin 30 to 60 minutes after taking it and last about 3 to 6 hours, followed by tiredness and sometimes low mood.

Interactions with antiretrovirals

MDMA is metabolised by CYP2D6. Several antiretrovirals inhibit or induce this enzyme, which may significantly change MDMA blood levels.

It may INCREASE MDMA levels

Higher levels may cause:

  • Hyperthermia (dangerously high body temperature)
  • Severe rise in blood pressure
  • Cardiac arrhythmias
  • Intense anxiety or agitation

It may DECREASE MDMA levels

Lower levels may cause:

  • Reduced or weaker-than-expected effects
  • Unpredictable changes in response

Medicines requiring more caution

Group / Medicine Interaction risk Notes
Protease inhibitors (PI): lopinavir/ritonavir, atazanavir, darunavir High CYP2D6 inhibition; may greatly increase MDMA levels and the risk of hyperthermia and cardiovascular toxicity
Integrase inhibitors: elvitegravir, raltegravir Moderate Elvitegravir boosted with cobicistat has greater interaction potential; raltegravir carries lower risk
NNRTIs: efavirenz, nevirapine Moderate May induce or inhibit CYP2D6; efavirenz may lower MDMA levels
Maraviroc Moderate Shared metabolic context; may be affected

Harm reduction

  • Use the smallest amount possible
  • Avoid combining with alcohol, cocaine, amphetamines, GHB, or other stimulants (this raises cardiovascular and serotonin syndrome risk)
  • Hydrate before and during use: moderate water intake, around 500 ml per hour of physical activity
  • Rest in cool, ventilated spaces
  • Avoid dancing for long periods without breaks
  • Tell your healthcare team about MDMA use so they can monitor possible interactions
  • Do not mix with SSRI antidepressants (serotonin syndrome risk)
  • Use drug checking kits to verify the substance

Warning signs

  • Fever or excessive sweating (very high temperature)
  • Chest pain or unusual palpitations
  • Intense nausea or vomiting
  • Confusion or agitation that does not improve
  • Muscle rigidity or tremors
  • Seizures

When should you seek medical care?

  • Body temperature above 38.5 C that does not come down
  • Chest pain or trouble breathing
  • Seizures or loss of consciousness
  • Persistent vomiting that does not improve
  • Very pale or bluish skin

If any of these happen, call emergency services immediately.

What does the evidence say?

Interactions between MDMA and protease inhibitors boosted with ritonavir are well documented. Ritonavir is a strong CYP2D6 inhibitor, which may sharply increase MDMA plasma levels and raise the risk of severe toxicity, including potentially fatal hyperthermia. Evidence with integrase inhibitors is more limited, although elvitegravir boosted with cobicistat has a similar interaction profile. It is important to tell the healthcare team so they can assess individual risk and adjust follow-up if needed.