|Systematic (IUPAC) name|
|[3-(2-dimethylaminoethyl)-1H-indol-4-yl] dihydrogen phosphate|
|Mol. mass||284.25 g/mol|
|Legal status||Prohibited (S9) (AU) Schedule III (CA) ? (UK) Schedule I (US)|
Psilocybin (pronounced /ˌsaɪlɵˈsaɪbɪn/ Sil-lə-SYE-bin) (also known as psilocybine) is a hallucinogenic (entheogenic, psychedelic) indole of the tryptamine family. It is produced by hundreds of species of fungi, including those of the genus Psilocybe, such as Psilocybe cubensis and Psilocybe semilanceata, and has also been reportedly isolated from about a dozen other genera. Collectively known as psilocybin mushrooms, these are commonly called "boomers," "sacred mushrooms," "magic mushrooms," or more simply "shrooms." Possession, and in some cases usage, of psilocybin or psilocin has been outlawed in most countries across the globe. Proponents of its usage consider it to be an entheogen and a tool to supplement various types of practices for transcendence, including in meditation, psychonautics, and psychedelic psychotherapy. The intensity and duration of entheogenic effects of psilocybin mushrooms are highly variable, depending on species or cultivar of mushrooms, dosage, individual physiology, and set and setting.
Once ingested, psilocybin is rapidly metabolised to psilocin, which then acts as a partial agonist at the 5-HT2A and 5-HT1A serotonin receptors in the brain. The mind-altering effects of psilocybin typically last anywhere from 3 to 8 hours; however, to individuals under the influence of psilocybin, the effects may seem to last much longer, since the drug can distort the perception of time.
The American ethnologist R. Gordon Wasson and his wife discovered that the ancient religious practices of the Indians in a remote village of Mexico included ingestion of mushrooms. In 1957, they published a Life magazine article (Seeking the Magic Mushroom), where they described the occurrence of hallucinatory experiences during these rituals. They were accompanied on a later expedition by the French mycologist Roger Heim, director of the Muséum national d'histoire naturelle, when it was possible to identify several of the fungi as Psilocybe species. Heim was able to successfully cultivate the mushroom in France, and sent samples to the Swiss chemist Albert Hofmann for analysis. Hofmann, who had previously discovered and experimented with LSD, was the first to recognize the importance and chemical structure of the pure compounds he called psilocybin and psilocin. Leading a research group that was able to isolate and identify the compounds from Psilocybe mexicana, Hofmann was aided in the discovery process by his willingness to ingest mushroom extracts. He and his colleagues later synthesized a number of compounds chemically related to the naturally occurring psilocybin:
These were essentially the same molecules except that: (1) the phosphoryl or hydroxy group at the top of the indole ring was moved around to other ring positions, and (2) different numbers of methyl groups (CH3) and other carbon chains were added to the side chains and to the nitrogen on the indole ring to see how these changes would affect psychoactivity.
Two diethyl (two ethyl groups in place of the two methyl groups) analogs of psilocybin and psilocin were synthesized by Hofmann, 4-phosphoryloxy-N,N-diethyltryptamine, called CY-19, and 4-hydroxy-N,N-diethyltryptamine, called CZ-74. Because their effects last only about three and a half hours (compared to roughly double that with psilocybin), they proved more manageable in European clinics using "psycholytic therapy"—psychotherapy in conjunction with the controlled use of psychedelics.
In the early 1960s, Harvard University became the testing ground of psilocybin, through the efforts of Timothy Leary and his associate Richard Alpert (now known as Ram Dass). Leary was able to obtain synthesized psilocybin from Hofmann through Hofmann's employer, Sandoz pharmaceutical (now Novartis). Although a number of experiments in the early 1960s demonstrated positive results using psilocybin in clinical psychiatry, the LSD hysteria of the times swept psilocybin along with it into the Schedule I category of illicit drugs in 1970. The 1970s would witness the emergence of psilocybin as the "entheogen of choice". This was due in large part to a wide dissemination of information on the topic, which even included fictional works such as those by Carlos Castaneda, and several books that taught the technique of growing one's own psilocybin mushrooms. One of the most popular of these books was produced under the pseudonyms O.T. Oss and O.N. Oeric by J. Bigwood, D.J. McKenna, K. Harrison McKenna and T.K. McKenna, entitled Psilocybin: Magic Mushroom Grower's Guide. Over 100,000 copies had been sold by 1981:
These authors adapted San Antonio's technique (for producing edible mushrooms by casing mycelial cultures on a rye grain substrate; San Antonio 1971) to the production of Psilocybe [Stropharia] cubensis. The new technique involved the use of ordinary kitchen implements, and for the first time the layperson was able to produce a potent entheogen in his own home, without access to sophisticated technology, equipment or chemical supplies.
Psilocybin is a naturally occurring compound found in varying concentrations in over 200 species of Basidiomycota mushrooms, distributed amongst the following genera: Psilocybe (116 species), Gymnopilus (14), Panaeolus (13), Copelandia (12), Hypholoma (6), Pluteus (6) Inocybe (6), Conocybe (4), Panaeolina (4), Gerronema (2) and Agrocybe, Galerina and Mycena (1 species each). The spores of these mushrooms do not contain psilocybin or psilocin. Mushroom caps tend to contain more of the psychoactive compounds than the stems. The total potency varies greatly between species and even between specimens of one species in the same batch. Younger, smaller mushrooms have a higher concentration of alkaloids and have a milder taste than larger, mature mushrooms. In general, the psilocybin content of mushrooms is quite variable (approximately 0.5–2% dry weight) and depends on species, growth and drying conditions, and mushroom size. Mature mycelium contains some psilocybin, while young mycelium (recently germinated from spores) does not contain appreciable amounts of alkaloids. Many species of mushrooms containing psilocybin also contain small amounts of the psilocybin analogs baeocystin and norbaeocystin. Most species of psilocybin-containing mushrooms bruise blue when handled or damaged due to the oxidization of phenolic compounds. This reaction, however, is not a definitive method of identification or determining a mushroom's potency.
Psilocybin (O-phosphoryl-4-hydroxy-N,N-dimethyltryptamine) is a prodrug that is converted into the pharmacologically active compound psilocin in the body by a dephosphorylation reaction. This chemical reaction takes place under strongly acidic conditions, or under physiological conditions in the body, through the action of enzymes called phosphatases. Psilocybin is a tryptamine compound having a chemical structure derived from tryptophan and containing a ring configuration called an indole linked to an ethylamine substituent. It bears a close structural resemblance to the neurotransmitter serotonin (5-hydroxytryptamine). Psilocybin is a zwitterionic alkaloid that is soluble in water, moderately soluble in methanol and ethanol, and insoluble in most organic solvents. Exposure to light is detrimental to the stability of aqueous solutions of psilocybin, and will cause it to rapidly oxidize—an important consideration when using it as an analytical standard. A method for the large-scale synthesis of psilocybin was reported by a Japanese group in 2003.
Many analytical techniques have been used to identify and evaluate the quantity of psilocybin in mushroom material. These techniques include thin layer chromatography, gas chromatography coupled to mass spectrometry (GC-MS), ion mobility spectrometry, capillary zone electrophoresis, ultraviolet spectroscopy, infrared spectroscopy, high performance liquid chromatography (HPLC) with ultraviolet, fluorescence, electrochemical, or electrospray mass spectrometric detection methods. The earliest techniques used gas chromatography, however, a problem with this method is that psilocybin dephosphorylates to psilocin prior to analysis, complicating the analysis.
Various chromatographic methods have been developed to detect psilocin in body fluids: the rapid emergency drug identification system (REMEDi HS), a drug screening method based on HPLC; HPLC with electrochemical detection; GC-MS; and liquid chromatography coupled to mass spectrometry. Although the determination of psilocin levels in urine can be performed without sample clean-up, the analysis in plasma or serum requires a preliminary extraction, followed by derivatization of the extracts in the case of GC-MS. A specific immunoassay has also been developed to detect psilocin in whole blood samples.
Psilocybin is rapidly dephosphorylated in the body to psilocin which then acts as a partial agonist at the 5-HT2A serotonin receptor in the brain where it mimics the effects of serotonin (5-HT). Psilocin is a 5-HT1A and 5-HT2A/2C agonist. The psychotomimetic effects of psilocin can be blocked in a dose-dependent fashion by the 5-HT2A antagonists ketanserin and risperidone. Psilocybin and psilocybin analogues have been used to help model the structure of the 5-HT2C G-protein coupled receptor.
Psilocybin has no recognized medical uses. However, it has been investigated as an experimental treatment for several disorders.
In 1961, Timothy Leary and Richard Alpert ran the Harvard Psilocybin Project, carrying out a number of experiments concerning the use of psilocybin in the treatment of personality disorders and other uses in psychological counseling.
A pilot study led by Francisco Moreno at the University of Arizona and supported by Multidisciplinary Association for Psychedelic Studies studied the effects of psilocybin on nine patients with obsessive-compulsive disorder (OCD). The study found that psilocybin could be safely given to patients with OCD, and it was associated with substantial reductions in OCD symptoms in several of the patients.
Two current studies are investigating the possibility that psilocybin can ease the psychological suffering associated with cancer. One study, led by Charles Grob, involves 12 subjects with terminal cancer being administered the hallucinogen or a placebo in two separate sessions. A second study, led by Roland Griffiths at Johns Hopkins, will administer psilocybin on two occasions to people "with a current or past diagnosis of cancer who have some anxiety or are feeling down about their cancer". In 2008, the Johns Hopkins research team published guidelines for responsibly conducting medical research trials with psilocybin and other hallucinogens in humans.
Additionally, psilocybin has shown promise to ease the pain caused by cluster headaches, often considered not only the most painful of all types of headaches, but "one of the worst pain syndromes known to mankind." In a 2006 study, 22 of 26 cluster headache patients reported successfully using psilocybin to abort the attacks, and 18 of 19 psilocybin users reported longer attack-free periods.
The toxicity of psilocybin is low; in rats, the oral LD50 is 280 mg/kg, approximately one and a half times that of caffeine. When administered intravenously in rabbits, psilocybin's LD50 is approximately 12.5 mg/kg (however rabbits are extremely intolerant to the effects of most psychoactive drugs). The lethal dose from psilocybin toxicity alone is unknown at recreational or medicinal levels, and has never been documented; a 2008 case report noted "Death from psilocybin intake alone is unknown at recreational or medicinal levels." Psilocybin makes up roughly 1% of the weight of Psilocybe cubensis mushrooms, and so nearly 1.7 kilograms of dried mushrooms, or 17 kilograms of fresh mushrooms, would be required for a 60 kg person to reach the 280 mg/kg LD50 rate of rats.
Psilocybin is absorbed through the lining of the mouth and stomach. Effects begin 10–40 minutes after ingestion of psilocybin-containing mushrooms, and last from 2–6 hours depending on dose, species, and individual metabolism. A typical recreational dosage is from 10–50 mg psilocybin. However, a very small number of people are unusually sensitive to psilocybin's effects, where a normal threshold dose of around 2 mg of psilocybin can result in effects usually associated with medium and high doses. Likewise, there are some people who require relatively high doses of psilocybin to gain low-dose effects. Individual brain chemistry and metabolism play a large role in determining a person's response to psilocybin.
Psilocybin is metabolized mostly in the liver where it becomes psilocin. It is broken down by the enzyme monoamine oxidase. MAO inhibitors have been known to sustain the effects of psilocybin for longer periods of time; people who are taking an MAOI for a medical condition may experience highly potentiated effects.
Mental and physical tolerance to psilocybin builds and dissipates quickly. Taking psilocybin more than three or four times in a week (especially on consecutive days) can result in diminished effects. Tolerance dissipates after a few days, so frequent users often keep doses spaced five to seven days apart to avoid the effect.
Research reported in 2008 concluded that, based on US data from the period 2000–2, adolescent-onset (defined here as ages 11–17) usage of hallucinogenic drugs (including psilocybin) did not increase the risk of drug dependence in adulthood; this was in contrast to adolescent usage of cannabis, cocaine, inhalants, anxiolytic medicines, and stimulants, all of which are associated with "an excess risk of developing clinical features associated with drug dependence".
The effects of psilocybin are highly variable and dependent on the current mood and overall sense of well-being by the individual. Initially the subject may begin to feel somewhat disoriented, lethargic, and euphoric or sometimes depressed. At low doses, hallucinatory effects may occur, including enhancement of colors and the animation of geometric shapes. Closed-eye hallucination may occur, where the affected individual may see multi-colored geometric shapes and vivid imaginative sequences. At higher doses, hallucinatory effects increase and experiences tend to be less social and more introspective or entheogenic. Open-eye visuals are more common, and may be very detailed although rarely confused with reality. Based on a study of 27 hospital admissions of patients (ages ranging from 12 to 24 years) who consumed Psilocybe semilanceata, a 1980 clinical report summarized the distribution of clinical symptoms of psilocybin overdose as follows: perceptual disorder (23 patients), mydriasis (pupil dilation) (20), dysphoria (an unpleasant mood) (13), hyperreflexia (twitching) (12), tachycardia (increased heart rate) (10), drowsiness (7), and euphoria (elation) (5). These clinical responses are similar to results obtained in several earlier studies where pure psilocybin was administered to human volunteers.
Distortions in the experience of time in psilocybin-induced states have been subjectively reported, and objectively measured. In these studies, psilocybin significantly decreased subjects’ reproduction of time intervals longer than 2.5 seconds, impaired their ability to synchronize to inter-beat intervals longer than 2 seconds, and reduced their preferred tapping rate. Recent studies into the effects of psilocybin on time interval reproduction may shed light on qualitative alterations of time experience in experimentally-induced altered states of consciousness, mystical states, or in psychopathology.
Users having a pleasant experience can feel ecstatic, a sense of connection to others, nature, the universe, and other feelings/emotions are often intensified. The vernacular term "bad trip" describes a reaction accompanied by fear of varying degrees, other substantial unpleasant feelings or sometimes dangerous behavior. Bad trip is generally used to describe a reaction which is primarily characterized by fear or other unpleasant emotions, not just transitory experience of such feelings. A variety of reasons may contribute to a psilocybin user experiencing a bad trip, including "tripping" during an emotional or physical low, or in a non-supportive/inadequate/etc. environment (see: set and setting); ingesting psilocybin in combination with other drugs or with alcohol can also induce a bad trip. Latent psychological issues may be triggered by the strong emotional components of the experience.
Some of these individuals report that they have experienced a 'spiritual' episode. For example, in the Marsh Chapel Experiment, which was run by a graduate student at Harvard Divinity School under the supervision of Timothy Leary, almost all of the graduate degree divinity student volunteers who received psilocybin reported profound religious experiences.
In 2006, a group of researchers from Johns Hopkins School of Medicine led by Roland R Griffiths conducted an experiment assessing the degree of mystical experience and attitudinal effects of the psilocybin experience; this report was published in the journal Psychopharmacology. Thirty-six volunteers without prior experience with hallucinogens were given psilocybin and methylphenidate (Ritalin) in separate sessions, the methylphenidate sessions serving as a control and psychoactive placebo; the tests were double-blind. The degree of mystical experience was measured using a questionnaire on mystical experience developed by Ralph W Hood; 61% of subjects reported a "complete mystical experience" after their psilocybin session, while only 13% reported such an outcome after their experience with methylphenidate. Two months after taking psilocybin, 79% of the participants reported moderately to greatly increased life satisfaction and sense of well-being. About 36% of participants also had a strong to extreme “experience of fear” or dysphoria (i.e., a “bad trip”) at some point during the psilocybin session (which was not reported by any subject during the methylphenidate session), with about one-third of these (13% of the total) reporting that this dysphoria dominated the entire session. These negative effects were reported to be easily managed by the researchers and did not have a lasting negative effect on the subject’s sense of well-being. Further measures at 14 months after the psilocybin experience confirmed that participants continued to attribute deep personal meaning to the experience.
Further studies by this group have investigated the relationship of psilocybin dose to likelihood of mystical experience in healthy volunteers. A double-blind study showed that psychedelic mushrooms could provide people an experience with substantial personal meaning and spiritual significance. In the study, one third of the subjects reported that ingestion of psychedelic mushrooms was the single most spiritually significant event of their lives, and over two-thirds reported it among their five most meaningful and spiritually significant events. On the other hand, one-third of the subjects reported extreme anxiety. Related research being conducted by this group is investigating whether mystical experiences in volunteers given psilocybin can help with anxiety and poor mood due to cancer.
Some reports have described cardiac complications that have occurred after the consumption of psychoactive fungi. A 1998 report described an 18-year old male suffering from arrhythmias and heart attack after eating P. semilanceata. A 2007 report described a male who developed symptoms similar to Takotsubo cardiomyopathy, characterized by a sudden temporary weakening of the myocardium (cardiac muscle).
Panic reactions can occur after consumption of psilocybin-containing mushrooms, especially if the ingestion is accidental or otherwise unexpected. For example, reactions such as violence, aggression, homicidal and suicidal attempts, , prolonged schizophrenia-like psychosis and convulsions have been reported in the literature. The similarity of psilocybin-induced symptoms to those of schizophrenia has led to the drug being used in both behavioral and neuroimaging studies of this psychotic disorder. In both cases, psychotic symptoms are thought to arise from a "deficient gating of sensory and cognitive information" in the brain that ultimately lead to "cognitive fragmentation and psychosis".
In the United States, psilocybin (and psilocin) were first subjected to federal regulation by a law that is commonly referred to as "the Drug Abuse Control Amendments of 1965". This law, a product of a bill sponsored by Senator Thomas J. Dodd, was passed in July of 1965 and took effect on February 1, 1966. The law was an amendment to the federal Food, Drug and Cosmetic Act and was intended to regulate the unlicensed "possession, manufacture, or sale of depressant, stimulant and hallucinogenic drugs”. The statutes themselves, however, did not list the "hallucinogenic drugs" that were being regulated. Instead the term "hallucinogenic drugs" was meant to refer to those substances that supposedly have a "hallucinogenic effect on the central nervous system".
Despite the seemingly strict provisions of the law, many people were exempt from prosecution. Specifically the statutes "permit[ted]… people to possess such drugs so long as they were for the personal use of the possessor, a member of his household, or for administration to an animal". The federal law that specifically banned psilocybin and psilocin was enacted on October 24, 1968. The latter substances were said to have "a high potential for abuse", "no currently accepted medical use" and "a lack of accepted safety". And, finally, on October 27, 1970, both psilocybin and psilocin became classified as Schedule I and were simultaneously labeled "hallucinogens" under a section of the “Comprehensive Drug Abuse Prevention and Control Act” known as the "Controlled Substances Act". Schedule I drugs are illicit drugs that are claimed to have no known therapeutic benefit. Parties to the treaty are required to restrict use of the drug to medical and scientific research under strictly controlled conditions. Most national drug laws have been amended to reflect this convention (for example, the US Psychotropic Substances Act, the UK Misuse of Drugs Act 1971, and the Canadian Controlled Drugs and Substances Act), with possession and use of psilocybin and psilocin being prohibited under almost all circumstances, and often carrying severe legal penalties.
Possession and use of psilocybin mushrooms, including the bluing species of Psilocybe, is therefore prohibited by extension. However, in many national, state, and provincial drug laws, there is a great deal of ambiguity about the legal status of psilocybin mushrooms and the spores of these mushrooms, as well as a strong element of selective enforcement in some places. Additionally, there has been a general shift in attitudes regarding research with psilocybin and other hallucingenic agents; after a long moratorium on the use of these drugs, many countries are revising their positions and have started to approve studies to test the physiological and therapeutic effects of hallucinogens. For more details on the legal status of psilocybin mushrooms and Psilocybe spores, see: Psilocybe: Social and legal aspects.
The substance is used as a recreational drug. It is illegal in many countries.