Yes, but it is no longer employed as a truth serum because it’s believed to be ineffective, and because it’s use is prohibited by law.
The use of Sodium Pentothal as a truth serum features prominently in many thrillers and spy films (and Meet the Fockers which was the inspiration for this post). However, it feels as though this could just be a convenient cinematic device rather than a real compound.
It turns out that it is real. Sodium Pentothal is a brand name owned by Abbott Laboratories. The compound is actually called thiopental sodium. To all of the chemistry nerds out there, here’s the chemical formula – C11H17N2NaO2S.
What is it used for?
Thiopental is a general anesthetic that acts quickly but only for a short time. This property makes it suitable for surgery on pregnant women because it has no effect on the fetus.
In addition to its beneficial use in medical anesthesia, sodium thiopental was formerly used as the first drug in a three-drug lethal injection series. This use was discontinued de facto when Hospira, the only US manufacturer, stopped making it, and the European Union banned exporting it for death penalty purposes.
Is it a “truth serum”?
Thiopental sodium is one of a group of drugs called barbiturates. Barbiturates were once commonly used in aiding sleep and reducing anxiety, and enjoyed a period of popularity as recreational drugs. Unfortunately, they are also highly addictive, and dangerous.
Although it was originally developed as an anaesthetic, it was soon noticed that when patients were in that twilight zone halfway between consciousness and unconsciousness, they became more chatty and disinhibited. After the drug had worn off, the patients forgot what they had been talking about.
It is theorized that sodium thiopental inhibits higher cortical functions. Since lying is presumed to require more concentration and mental effort than telling the truth, most people would be more likely to default to telling the truth.
In the first half of the twentieth century, the drug was used by some psychiatrists to draw to the surface hidden truths from that patients were unable or unwilling to reveal. Law enforcement and intelligence also began to depend on this and other so-called “truth serums”.
Is it effective or legal?
No, it is neither effective nor legal.
It turned out the connection between higher brain function and truthfulness is questionable. The answer could come from the person’s imagination, or the least complex answer is actually the one subject thinks the interrogator wants to hear (i.e. a confession).
In 1963 the US Supreme court ruled that confession statements made under the influence of truth serum drugs was “unconstitutionally coerced” threatening citizens’ rights under the fifth amendment and was therefore inadmissible.
So Sodium Pentothal does exist and history shows that it was used as a truth serum. History also tells us that, for the most part, it probably wasn’t very effective. With that said, it’s unlikely that Hollywood will soon give up such a convenient plot device.