"Today, the medical value of hallucinogens is again being examined in formal psychiatric settings. One substance under investigation is psilocybin, 4-phosphoryloxy-N,N-dimethyltryptamine, which occurs in nature in various species of mushrooms. Psilocybin is rapidly metabolized to psilocin, which is a potent agonist at serotonin 5-HT1A/2A/2C receptors, with 5-HT2A receptor activation directly correlated with human hallucinogenic activity.16 Psilocybin was studied during the 1960s to establish its psychopharmacological profile; it was found to be active orally at around 10 mg, with stronger effects at higher doses, and to have a 4- to 6-hour duration of experience. Psychological effects were similar to those of lysergic acid diethylamide (LSD), with psilocybin considered to be more strongly visual, less emotionally intense, more euphoric, and with fewer panic reactions and less chance of paranoia than LSD."17,18
Grob, Charles S.; Danforth, Alicia L.; Chopra, Gurpreet S.; Hagerty, Marycie; McKay, Charles R.; Halberstadt, Adam L.; Greer, George R., "Pilot Study of Psilocybin Treatment for Anxiety in Patients With Advanced-Stage Cancer," Archives of General Psychiatry, (Chicago, IL: American Medical Association, January 2011), Volume 68, Number 1, p. 71.