A standard Department of Transportation (DOT) drug test in 2026 scans for five primary classes of prohibited substances: Marijuana (THC), Cocaine, Opiates (including codeine, morphine, and heroin), Amphetamines (including meth and MDMA), and Phencyclidine (PCP). In 2026, the list has been updated to include specific synthetic opioids like fentanyl and tramadol, as well as semi-synthetic ones like hydrocodone and oxycodone. It is a vital warning that even in states where recreational marijuana is legal, DOT-regulated employees (like pilots, truck drivers, and sea captains) are strictly prohibited from using any THC products, as federal law still classifies it as a Schedule I substance. Additionally, the 2026 World Anti-Doping Agency (WADA) list—which influences many professional standards—has clarified that non-diagnostic carbon monoxide use and certain "performance-enhancing" nuclei/cell components are also under scrutiny for specific safety-sensitive positions.