Baeocystin is a mushroom alkaloid and analog of the psychedelic hallucinogenic drug psilocybin, a tryptamine derivative. It is found as a minor compound in most psychoactive mushrooms together with psilocybin, norbaeocystin, and psilocin. Little information exists with regard to human pharmacology, but in the book Magic Mushrooms Around the World, author Jochen Gartz reports being aware of a study in which "10 mg of baeocystin were found to be about as psychoactive as a similar amount of psilocybin."^{[citation needed]}

First isolated from the mushroom Psilocybe baeocystis, and later from P. semilanceata (Repke & Leslie 1977) and first synthesized by Troxler et al. (1959) Baeocystin is a demethylated derivative of psilocybin.

Bad Acid Trip is an American metal band, currently signed to System of a Down lead singer Serj Tankian's record label, Serjical Strike Records. Their 2004 album, Lynch the Weirdo, was produced by Daron Malakian, another System of a Down member. In 2006 they performed on the second stage at the Ozzfest summer tour. The band has three full-length releases (For the Weird by the Weird, Lynch The Weirdo, and Humanly Possible) and multiple EPs. According to the band's official website, they just released their newest album, titled Humanly Possible on May 3, 2011. The EP Symbiotic Slavery was released on August 18, 2009 in order to fill the large gap between Lynch The Weirdo and Humanly Possible. The band is recognizable as being one of the more coherent grindcore acts.