Water poisoning (hyponatremia)

Because overheating is one of the most dangerous acute risks of ecstasy/MDMA use, many MDMA users know they should “drink plenty of water”. Some users have interpreted this to mean you should “drink a lot of water” when taking MDMA. Unfortunately, however, there have been cases where MDMA users have died from drinking “too much” water; water poisoning.

MDMA causes your kidneys to excrete less water through your urine. So your body retains more fluid after taking MDMA. It also makes urinating difficult, or even impossible. If you drink a lot of water, it will increase the volume of circulating blood. The concentration of electrolytes (such as sodium) in your blood decreases. In addition, MDMA use often decreases feelings of hunger. This ensures that you are less likely to ingest salts (sodium). Women are more likely to be affected by this than men.
Due to this low concentration of sodium, water from the blood flows into the cells of the brain, causing them to swell. Because the bone in your skull can’t expand, the pressure inside increases. This increased cranial pressure causes problems with normal brain function. Without intervention, this can lead to a coma and eventually death in extreme cases.

The most important way to avoid water intoxication is to avoid drinking too much water.

Unity tip: don’t drink too much water when you use XTC/MDMA and in the 24 hours after use. Stick to a maximum of 1 glass of water per hour.

Symptoms of water intoxication are:

  • Nausea
  • Vomiting
  • Headache
  • Paranoia
  • General discomfort


Severe symptoms requiring immediate hospitalization:

  • Seizures
  • Impaired consciousness
  • Coma

We created this video in 2015 which shows exactly how water intoxication works in your body and how you can prevent it.