MDMA can increase your heart rate and blood pressure, which may be harmful if you already have a cardiovascular condition.

MDMA (3,4-methylenedioxy-methamphetamine) is a synthetic drug that elevates energy levels and alters the perception of time and sensory experiences. It became popular in the nightclub scene for its ability to enhance euphoria, pleasure, and sexuality.

Also called molly or ecstasy, MDMA is illegal in the United States, though there’s ongoing research about its potential benefits in a mental health setting.

While most people associate negative MDMA reactions with symptoms like anxiety, muscle tension, or hyperthermia, the cardiac effects of MDMA are also something to consider.

The cardiovascular system includes the heart and blood vessels. MDMA affects the cardiovascular system by increasing heart rate and raising blood pressure.

MDMA can affect your heart independently of your blood vessels, however. Research shows the cardiac effects of MDMA extend beyond high blood pressure and racing heart rate.

Occasional periods of increased heart rate and blood pressure typically aren’t a medical concern. However, heavy MDMA use, or using MDMA when you already have high blood pressure or other preexisting heart conditions, can increase the risk of these complications below.

Cardiac contractile dysfunction

When the heart doesn’t pump correctly, staying relaxed for too long and not contracting enough, it’s known as cardiac contractile dysfunction.

Cardiac contractile dysfunction can potentially cause heart failure. At this point, the heart can’t pump blood at the rate the body needs to maintain proper function.


Arrhythmias are irregularities in the rhythm of your heart rate. They can be brief or last long enough to make you feel symptoms, such as a racing heart.

An arrhythmia indicates an issue with the electrical signals that cue your heart to pump.

While many people live with a mild arrhythmia and do not experience significant health effects, untreated arrhythmias can cause major cardiac events, like stroke, heart failure, or cardiac arrest.

Myocardial necrosis

Myocardial necrosis is the death and scarring of heart tissue. It occurs when the heart is deprived of the proper level of oxygen.

Myocardial necrosis often occurs alongside a heart attack (myocardial infarction). A heart attack occurs when the lack of oxygen to the heart becomes extreme enough to cause a large portion of the heart to start to die.

Valvular heart disease

The cardiac effects of MDMA use can also involve specific areas of your heart, like the valves, which control blood flow through the chambers of the heart.

Valvular heart disease occurs when any of the four heart valves become damaged and can’t fully open to allow maximum blood flow.

Dilated cardiomyopathy

Dilated cardiomyopathy is another form of heart weakening. It occurs when the left ventricle (and sometimes the right) in the upper part of the heart expands, preventing the chamber from contracting at full strength.

Dilated cardiomyopathy can lead to arrhythmias and may cause valve dysfunction.

Can molly cause a heart attack?

Yes. It’s possible for MDMA to cause a heart attack by compromising the heart’s oxygen supply and causing tissue death.

However, instances of this happening are quite rare, and the majority of documented cases involved cardiovascular risk factors (like family history of heart attack) or other drugs, like alcohol or cocaine.

If you have already had a heart attack or are at risk of one, MDMA use is not recommended. It’s also important to not mix MDMA with alcohol or other substances.

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MDMA is typically used in social settings. Communicating potential early signs of heart attack with your friends before using MDMA may help everyone be mindful of comments like, “I feel like my heart is racing.”

Signs and symptoms you or a friend may need emergency cardiac care include:

If you notice any of these symptoms in yourself or others, contacting emergency responders as soon as possible could save your heart health and your life.

Learn more about how to use CPR during a cardiac event here.

Rapid heart rate is a known side effect of MDMA. It doesn’t always mean you’re in immediate danger, but returning your pulse to a safer level as soon as possible can help protect your heart.

If MDMA is causing your racing heart, you may not be able to slow it down without medical intervention.

Unlike psychological causes of increased heart rate, like anxiety, traditional relaxation techniques might not be enough. Emergency medications may be necessary to fully counteract the cardiac effects of MDMA.

Until you see a doctor, you can try lowering your heart rate by taking deep, controlled breaths or trying a Valsalva maneuver.

Valsalva maneuvers are techniques that temporarily increase the pressure in your chest to normalize a fast heart rate.

The simplest way to perform a Valsalva maneuver is to:

  1. Close your mouth and pinch your nose.
  2. Attempt to exhale but do not open your mouth or nose.
  3. Contract your abdomen, as if you’re passing a bowel movement.
  4. Hold for up to 15 seconds, and then relax.

Getting support

If you or someone you know wants to learn more about how to stop using MDMA, you can find support services and resources at:

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MDMA is a drug that alters perception and sensory experiences. MDMA is an illegal substance in the United States because it has a high chance of misuse and negative health effects.

The cardiac effects of MDMA go beyond high blood pressure and racing pulse. MDMA can cause major cardiac events due to improper blood flow and impaired heart function.