Psilocybin is a naturally occurring psychedelic compound produced by more than 200 species of
mushrooms, collectively known as psilocybin mushrooms. Psilocybin
(4-phosphoroyloxy-N,N-dimethyltryptamine) is a hallucinogenic tryptamine that was first
isolated from Psilocybe mushrooms in 1957. The objective of this Phase I clinical trial is to
determine the pharmacokinetics of oral doses of psilocybin in normal, healthy adults. The
study is performed in support of Phase II and Phase III studies of psilocybin for the
treatment of refractory anxiety associated with incurable cancer, as well as other possible
indications. Psilocybin is at present not an FDA-approved drug.