"Truth serum" is a colloquial name for any of a range of psychoactive drugs used in an effort to obtain information from subjects who are unable or unwilling to provide it otherwise. These include ethanol, scopolamine, 3-quinuclidinyl benzilate, midazolam, flunitrazepam, sodium thiopental, and amobarbital, among others.

Amobarbital is a drug that is a barbiturate derivative. It has sedative-hypnotic properties. It is a white crystalline powder with no odor and a slightly bitter taste. It was first synthesized in Germany in 1923. It is considered a short to intermediate acting barbiturate. If amobarbital is taken for extended periods of time, physiological and psychological dependence can develop. Amobarbital withdrawal mimics delirium tremens and may be life-threatening. Amobarbital was manufactured by Eli Lilly and Company in the US under the brand name Amytal in bright blue bullet shaped capsules or pink tablets containing 50, 100, or 200 milligrams of the drug. The drug was also manufactured generically. Amobarbital was widely misused, known as "Blue Heavens" on the street. Amytal, as well as Tuinal, a combination drug containing equal quantities of secobarbital and amobarbital, were both manufactured by Eli Lilly until the late-1990s. However, as the popularity of benzodiazepines increased, prescriptions for these medications became increasingly rare beginning in the mid to late-1980s.