Two doctoral students identify four metabolites of psilocybin in human plasma and urine using high-performance liquid chromatography (HPLC). They publish their findings in their respective dissertations and they are summarized by Torsten Passie, et al., in 2002. The metabolites are:
- 4-hydroxy-N,N-dimethyltrypt-amine (psilocin)
- 4-hydroxyindole-3-yl-acetaldehyde (4H1A)
- 4-hydroxyindole-3-yl-acetic-acid (41-IIAA)
- 4-hydroxytryptophol (41-IT).