Adrenochrome is a chemical compound with the molecular formula C9H9NO3 produced by the oxidation of adrenaline (epinephrine). The derivative carbazochrome is a hemostatic medication. Despite a similarity in chemical names, it is unrelated to chrome or chromium.
Where have I heard of adrenochrome?
Aldous Huxley’s 1954 essay “The Doors of Perception”, written mostly about his experiences with mescaline, discusses the possibility that adrenochrome is a compound with similar effects to the psychedelic cactus. He has not taken it, and doesn’t know how one would obtain it, saying just that it’s spontaneously produced by the human body. He describes it as “a product of the decomposition of adrenaline”, which is, surprisingly, correct.
There’s a brief mention of “drencrom” in the 1962 novel A Clockwork Orange, where it’s an optional addition to the cocktail (glass of milk) Moloko Plus, but probably the most cited use of the compound is in Hunter S Thompson’s Fear and Loathing in Las Vegas. It might be a novel, but many assumed it was a real thing that people really did. Thompson did not explain the adrenochrome buzz in great detail, but this probably isn’t too far from his vision:
http://thespinoff.co.nz/society/07-04-2020/explainer-adrenochrome-the-drug-that-doesnt-exist/

Realist - Everybody in America is soft, and hates conflict. The cure for this, both in politics and social life, is the same -- hardihood. Give them raw truth.