The synthetic stimulant 2-Cl-4,5-MDMA, an NPS linked to severe intoxications, increased dopamine and serotonin levels in the nucleus accumbens shell and medial prefrontal cortex of rats in a dose-, brain area-, and age-dependent manner. In adult rats, dopamine rose more markedly in both brain areas, while adolescent rats showed a greater serotonin increase in the nucleus accumbens shell. The drug stimulated locomotion and stereotyped activity more in adolescents but did not trigger 50-kHz ultrasonic vocalizations, suggesting no positive affective properties. These findings indicate age-dependent neurochemical and behavioral effects, helping to assess health risks from human use.
Tablets sold as MDMA frequently contain psychoactive adulterants that vary by region and year, potentially increasing central nervous system harm. A review of studies from 2020 to 2025 covering Continental Europe, the UK, the USA, and Australia found that co-administration of MDMA with common adulterants can exacerbate noxious neurological and psychiatric effects. The composition of tablets differs across these regions, and interactions between MDMA and adulterants may explain some adverse effects seen in users. Expanding drug checking and public health efforts is essential to inform users, first responders, and healthcare professionals about these risks.