4-AcO-DMT (also known as O-Acetylpsilocin, 4-Acetoxy-DMT, or Psilacetin) is a synthetically produced psychedelic tryptamine. It is the acetylated form of the psilocybin mushroom alkaloid psilocin and is a lower homolog of 4-AcO-DET, 4-AcO-MiPT and 4-AcO-DiPT.
The compound has been suggested by David Nichols to be a potentially useful alternative to psilocybin for pharmacological studies as they are both believed to be prodrugs of psilocin. Its structural similarities to psilocin and psilocybin results in an identical subjective effect profile and the three compounds can be said to feel indistinguishable from each other. This allows 4-AcO-DMT to function as a perfect substitute for psilocybin mushrooms.