caffeine, nicotine, amphetamine, methamphetamine crystal meth, mdma, fentanyl, ketamine, tetrahydrocannabinol, mescaline.

agent alkaloid amphetamine analgesic atom atomic caffeine carbon chemical chemistry crystal drug ecstasy fentanil fentanyl formula hydrogen illustration ketamine mdma mescaline meth methamphetamine molecular molecule narcotic nicotine opioid organic oxygen pain psychoactive recreational structural structure tetrahydrocannabinol thc vector