America has been fighting the War on Drugs for decades, but drug cartels, suppliers, and dealers seem to be always one step ahead of the authorities. President Trump has declared the cartels as "terrorists" and labelled fentanyl, the powerful synthetic opioid, a "weapon of mass destruction". However, the drug supply is evolving, with other deadly synthetics being introduced, including strong animal tranquilizers, known on the streets as "tranq".