Ecstasy (MDMA) is a mood-lifting drug with numerous somatic side effects, for example, dehydration or continuous chewing and biting. We describe the case of a young woman who underwent a forensic medical examination for suspected sexual assault. She claimed to have suffered from a memory lapse, and she had a painful swelling of her lips with a plaque-like coating on her lips and buccal mucosa. The attending physician suspected that these findings might have been caused by strong sucking pressure on her lips within the context of a sexual assault. A toxicological examination of a blood specimen verified that she had been under the influence of an extremely high dose of ecstasy (1.456 mg/L MDMA and 0.0213 mg/L MDA). Pursuant to the forensic medical assessment, the described findings on her lips, and buccal mucosa were interpreted as an allergic and mechanical reaction (through continuous chewing and biting) to ecstasy.