Introduction to Psilocybin
Psilocybin is the phosphate ester of psilocin. It is one of the psychoactive chemicals present in mushrooms from a multitude of genera, most notably Psilocybe (along with psilocin, baeocystin and norbaeocystin), collectively referred to as Magic Mushrooms. Psilocybin is metabolized in the body to psilocin.
Ways of administrationPsilocybin is most commonly used orally (in the form of dried mushrooms), but for research purposes it's also been used intravenously.
Effects of Psilocybin
Combinations with Psilocybin
Different Uses for Psilocybin
Pharmacology of PsilocybinLD50 (mg/kg)  :
Mice : 285 intravenously
Rat : 280 intravenously
Rabbit : 12.5 intravenously
Chemistry of Psilocybin
Column 1 Column 2 Systematic (IUPAC) name: [3-(2-Dimethylaminoethyl)-1H-indol-4-yl] dihydrogen phosphate Synonyms: 3-[2-(Dimethylamino)ethyl]-1H-indol-4-ol 4-(dihydrogen phosphate), O-phosphoryl-4-hydroxy-N,N-dimethyltryptamine, Indocybin Molecular Formula: C12H17N2O4P Molar mass: 284.25 g/mol  CAS Registry Number: 520-52-5 Melting Point: 220-228°C (crystals from boiling water), 185-195°C (crystals from boiling methanol) Boiling Point: no data Flash Point: no data Solubility: soluble in 20 parts boiling water, 120 parts boiling methanol; slightly soluble in ethanol; practically insoluble in chloroform, benzene; slightly soluble in ether, acetone; insoluble in hexane Additionnal data: pH 5.2 in 50 % aqueous ethanol Notes: crystallized from water or methanol
The LD50 of psilocybin is 280 milligrams per kilogram (mg/kg), and approximately 12.5 mg/kg when administered intravenously in rabbits.
Considering the average Psilocybe cubensis is 1% psilocybin by weight it would take 37lbs (17kg) of fresh mushrooms, or 1.3lbs (1.7kg) of dry mushrooms for a 130 lb (60kg) adult to reach the LD50.
*Stamets, Paul. Psilocybin Mushrooms of the World. 1996
Reagent test results of Psilocybin
Reagent color produced Marquis Dull Orange Frohede's Grey blue -> green -> yellow
The dangers of PsilocybinThese are the dangers common to all psychedelic drugs:
Accidental injury. When on a psychedelic drug, it is easier to accidentally injure yourself. Also because of the disorientating and potentially delusion inspiring nature of the experience, you could be lead to inflict harm on others or yourself. People have fallen off rooftops, run into traffic, attempted to throw people off rooftops as 'sacrifices', drowned, and so on. The best way of protecting against this is to have a friend with you who is sober to look after you and handle any negative situation that might arise.
Bad trips. A bad trip is a negative psychedelic experience. It can range from a mildly negative feeling of anxiety/discomfort, to full-blown psychosis. Bad trips usually ruin a psychedelic experience for the tripper and everyone else. Most bad trips are manageable, just very uncomfortable and difficult. Some are extreme and unmanageable though. It's not uncommon for a bad trip to result in lingering psychological issues. Usually just a few days of negative emotions and anxiety. Sometimes, however, a week or so of serious anxiety, destabilized mental state and impaired functioning is possible. On very rare occasions, a month or two of severely diminished functioning, traumatized mental state, depression & crippling anxiety can occur. More information on bad trips can be found here. The best way of avoiding a bad trip is having the correct set and setting.
Permanent psychosis. Psychedelics are believed by researchers not to cause permanent psychosis, however they could trigger a latent mental illness in someone who was already predisposed to it, or make existing mental illnesses worse. If there is a history of mental illness in your family, you are more likely to be predisposed. Everyone is at some risk, however.
PTSD, anxiety disorder, depression & depersonalization. There are anecdotal reports of the trauma inflicted by some bad trips leading to depression and anxiety which while usually temporary, could potentially develop into lasting disorders. While no different to the potential of any traumatic event to cause lasting disorders, nonetheless this is a danger of psychedelic drug use.
Forms of Psilocybin
Legal status of Psilocybin
Psilocybin is a controlled substance 21 CFR 1308.11
History of Psilocybin
More Psilocybin Sections
The latest Psilocybin threads
Calculated from Atomic Weights of the Elements, 2007
Merck Index, fifteenth edition (2013)
 psilocybin monograph