We're currently seeing an increase in the popularity of music festivals and electronic music, and with that, we are seeing an increase in drug use, most notably, MDMA, "Molly," or ecstasy. While the drug increases in popularity, knowledge around the drug is not well-known, among users and non-users. While I do not condone the use of MDMA (I myself have not tried it), I do think those who are using it should know the risks, and a general better knowledge of how any drug works should increase public safety. People who are going to use drugs are going to continue doing so, and it is important they do so safely.
According to a UK study on various recreational drugs and their risk of harm, ecstasy (a form of MDMA) is one of the less harmful recreational drugs, in terms of harm to the user and harm to others. In contrast, alcohol, heroin, and crack cocaine are the most harmful to both the individual, and others, as well. You can see the results below.
While ecstasy itself is less harmful than many other popular drugs, it is not 100% safe, as no substance use ever is.
There are many complications with the use of MDMA. First, it's important to note that according to the Multidisciplinary Association for Psychedelic Studies (MAPS), MDMA can be useful for treating PTSD and other disorders, but use of the drug must be carefully limited. Frequent use of MDMA may eventually lead to serotonin syndrome.
Secondly, it's also important to note that the use of MDMA is safest when it is pure, and it's difficult to tell when MDMA is pure or not. Many drugs sold as "ecstasy" or "Molly" may contain MDMA, but also contain other substances, including but not limited to, caffeine, methamphetamine, or more recently, Fentanyl. Fentanyl is a synthetic opioid that is stronger than morphine and very deadly. Many recent overdoses have been caused by the popular drug. 56% of last year's overdoses in British Columbia were because of Fentanyl in heroin, cocaine, etc. Deaths due to Fentanyl overdose in Florida have increased 135% in the past year alone. There are test kits for MDMA to make sure what you are getting isn't laced with other drugs, but not all of these tests can detect Fentanyl.
Lastly, the most frequent reason for death after use of MDMA (other than using it in combination with other drugs) is dehydration/heatstroke. In many environments where MDMA is taken (such as a music festival), users may partake in aerobic activity (dancing). That, coupled with high temperatures and insufficient water/electrolytes, causes dehydration and hyperthermia. Thus it is important to remember to keep yourself hydrated if you are going to do MDMA (although, in very rare cases, too much water may cause hyponatremia).
All in all, I would advise any users (or potential users) to understand that no drug is 100% safe, and that includes MDMA. If you are going to do it, be careful. For more information, look at RollSafe.org.