 It is theorized to be a prodrug of psilocin, as is psilocybin, which occurs naturally in many species of hallucinogenic mushrooms.This is because the aromatic acetyl moiety on the 4th position of the indole ring system is subject to deacetylation in acidic conditions such as those found in the stomach.Psilacetin is "O"-acetylated psilocin, whereas psilocybin is "O"-phosphorylated.