The demand for MDMA (methylenedioxymethamphetamine) has increased, especially among teenagers 12 to 18 years old. It is estimated that approximately 2.8 million teens have at least tried this drug. Coincident with this trend has been an increasing body of literature that questions the safety of MDMA consumption in terms of possibly permanent neurological damage, associated with behavioral and functional deficits. Whatever the likelihood of those risks, there have been well-documented problems with dehydration, hyperthermia, rhabdomyolysis, disseminated intravascular coagulation, and multiple organ failure. In addition, there have been tablets sold which either contain no MDMA, and may be comprised of more dangerous chemicals, or may contain a mixture of both. The current response has been the emergence of several harm reduction strategies, including the publishing of pamphlets warning Ecstasy users to hydrate and cool themselves. Another has been the utilization of chemical tests of tablet shavings to observe color changes purported to help distinguish MDMA-containing tablets from substitutes. The utility of these tests and the consequences of their shortcomings are examined.