14 DAY TRIAL // The truth serum is a drug that would be injected into the muscles to extract information from persons resistant to deliver it, most often by a police, intelligence, or military organization and the concept turned popular due to espionage novels and movies.
Real truth drugs are mostly fictional, even if some chemicals have been shown to be effective in lowering the resistance of an interrogated person.
The term appeared at the beginning of the '20s, when the anaesthesiologist T.S. House baptized with commercial goals his discovery, the alkaloid scopolamine, extracted from plants belonging to the nightshade family, like henbane (Hyoscyamus), jimson weed (Datura species) and Scopolia (from this genus comes the name of the chemical). Even today, scolopamine is used as a sedative and mydriatic and to alleviate the symptoms of motion sickness.
House claimed that the drug could induce a person to tell the truth and during a trial for crime in Alabama (US), various persons confessed to be guilty under its effects. The news, picked up by the sensationalist media, contributed to the creation of the legend of the truth serum.
The employment of scopolamine as a truth drug was investigated by various secret services, including the CIA, during the 1950s, in the Project MKULTRA. But due to the hallucinogenic side effects of the alkaloid, the truth was prone to distortion and the project was after that abandoned. The infamous Nazi doctor Josef Mengele experimented on scopolamine as an interrogation drug.
After that, other narcotic serums emerged, like the amytal and sodium pentothal. Still, these drugs were never proved to have conclusive effects on somebody's will. It is true that high doses can diminish certain brain functions, particularly with judgment and higher cognitive functions, like counting or reasoning and remove inhibitions, but that's all.
Alcohol too is employed for this purpose by many individuals in a more innocent sense, but also by professionals, like KGB officers.