Users have reported a variety of mild physical symptoms such as jaw clenching, teeth grinding, eye wiggles, tightened muscles, sweating, chills, increased heart rate, blood pressure and body temperature, auditory effects, nausea, shaking, next-day sleepiness and sometimes intense depression from the lowering of Seratonin in the brain. Occasionally it can cause toxic reactions in people with asthma, heart conditions, diabetes, epilepsy, psychosis, or depression. E has been found to lower serotonin in the brain.

As far as long-term effects are concerned, the implications aren't completely known until further human testing is performed. Scientists suspect, however, based on animal testing, that some nerve damage and neurotransmitter depletion in the brain may occur with repeated usage. Most claims (such as that it causes Parkinsons disease or drains spinal fluid) actually refer to other drugs or common misconceptions.

The Parkinson's myth came about as a result of a confusion between MDMA and MPTP, a contaminant that is produced from a bad manufacture of a synthetic opiate. This contaminent has caused neural damage similar to Parkinson's disease to unfortunate recipients of contaminated opiates. MPTP is in no way related to MDMA, and has not been associated with MDMA manufacture.

The spinal fluid drainage myth started because some pharmacological studies are done by giving subjects MDMA, then withdrawing cerebrospinal fluid samples for analysis via spinal tap, the same way LSD is detected in the body. It is the researching of MDMA that drains spinal fluid, not the actual MDMA.