In the body, 4-AcO-DMT / psilacetin is thought to be deacetylated into psilocin during first pass metabolism and subsequent passes through the liver (evident as psilacetin is also active when injected). This has not been formally proven, however, and is based on reports that most users cannot tell the difference between these two compounds when ingested to the point that they are often considered as indistinguishable from each other in terms of their subjective effects.
