"Black Beauties" was the street name for a combination amphetamine capsule/tablet containing 10mg of amphetamine and 10mg of dextroamphetamine. The trade name of Black Beauties was Biphetamine 20.

Amphetamines are stimulants, and Biphetamine 20 was reportedly given to soldiers to decrease fatigue and keep them awake during active combat. Later Black Beauties were marketed as diet pills.

The use of Biphetamine 20 (Black Beauties) as a street drug exploded in the 1960s and 70s when people started taking it recreationally. At the time, Black Beauties were widely considered a cheap and legal alternative to cocaine and popular among people wanting to get “high” or to increase their wakefulness. It wasn’t until 1965 when they became illegal except on prescription and then the Controlled Substances Act was passed in 1970 that their use began to decline. Biphetamine 20 was withdrawn from the market in 1998.

Black Beauties contained an even, racemic mixture of dextroamphetamine and levoamphetamine that is very similar to Adderall which is still available today. Adderall contains an even mixture of dextroamphetamine sulfate, dextroamphetamine saccharate, amphetamine sulfate, and amphetamine aspartate monohydrate and is used to treat medical conditions such as attention deficit hyperactivity disorder (ADHD). Amphetamine and dextroamphetamine are both Schedule II controlled substances, with a high potential for abuse. They are very addictive and can increase heart rate and blood pressure, and are dangerous if not taken as prescribed.

Interest in Black Beauties soared after it made an appearance in the American comedy-drama, Russian Doll, when the main character traveled back in time and experimented with Black Beauties.