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OFFICIAL NAMES: Psilocybin, Psilocybe mushrooms

STREET NAMES: Magic mushrooms, shrooms, boomers, caps, cubes (Psilocybe cubensis), fungus, liberty caps, Mexican mushrooms, mushies, mushrooms, psychedelic mushrooms, psilocydes, purple passion, sillies, silly putty, simple Simon

DRUG CLASSIFICATIONS: Schedule I, hallucinogen


For thousands of years, Native Americans in Central and South America have used Psilocybe (mushrooms producing psilocybin—pronounced sill-o-sigh-bin) in rare religious rites and ceremonies. The Aztec word for these hallucinogen-producing mushrooms is teonanacatl, which roughly translates as "flesh of god." The shaman (medicine man or woman) and a select group of participants using the mushrooms believed they received special power to talk to the gods, to divine the future, to cure the sick, and to speak with the dead. In 2002, Native Americans in Central, South, and North America still practiced their religious traditions by legally using Psilocybe mushrooms.

In the 16th century, when the Spanish conquered the Aztecs, the Spanish tried to eradicate the use of the "magic or Mexican mushroom." The effort was unsuccessful, but in the process, the priests were able to document the traditions, uses, and history associated with the mushroom. Ingesting these mushrooms at that time was largely confined to the Native American population.

Most people in Europe and in the United States were not aware of Psilocybe mushrooms until 1957.

That year, R. Gordon Wasson, an enthnomycologist, published an article about Psilocybe mushrooms in Life magazine. This article brought the mushrooms to the attention of the general public for the first time. As a result of the article, thousands of people flocked to Mexico in search of the mind-altering mushroom. About that same time, the psychoactive chemical psilocybin was isolated and synthesized by Swiss chemist Albert Hofmann, who also discovered LSD (lysergic acid diethylamide).

For about a decade, psilocybin was legal and available in mushroom, powder, or pill form. It was used by psychologists to treat psychological problems and was also studied as a treatment for reforming criminals. By 1968, clinical tests were showing few positive, conclusive results and abuse of the mushroom in the United States was escalating. As a result of these findings, the government made possesion of psilocybin illegal.

As the Psilocybe mushroom gained popularity, so did knowledge about its native growth. Prior to the 1950s these mushrooms were only known to grow in Mexico and a few select places. It was soon discovered that Psilocybe mushrooms grow around the world. Many of them grow naturally in the United States, especially in the Pacific Northwest and southern states. This makes enforcing the law difficult.

While psilocybin use slowed in the 1980s, its renewed popularity since the mid-1990s is causing concern. In 2002, Psilocybe mushrooms are becoming more common at raves, college campuses, and clubs in the United States and several other countries. Psilocybe mushrooms are advertised as a "natural" hallucinogen that is safer and gentler than LSD.


Psilocybin is a naturally occurring hallucinogen. It exerts neurotoxic effects similar to LSD and has a chemical structure similar to the neurotransmitter serotonin in the human brain. Psilocybin is found as an indole alkaloid (nitrogen-containing organic base) in the fungal (Protista) kingdom. Often it is accompanied by the related alkaloids, psilocin, baeocystin, and norbaeocystin.

Mushrooms that contain psilocybin are of the genus Psilocybe and belong to the Basidiomycetes class. Over 90 Psilocybe species are psychoactive, and they grow naturally around the world. Psilocybin (phosphorylated 4-hydroxydimethyltryptamine) usually accounts for0.03 to 1.3% of the total weight of the mushroom, though potency can vary greatly.

Psilocybin can be isolated and crystallized or synthesized to nearly 100% purity. Research indicates that Psilocybe mushrooms produce a bitter alkaloid as an insecticide to protect itself from predators. In humans, psilocybin is a neurotoxin that can cause hallucinations.


Psilocybin powder

Psilocybin powder is the most potent form of this hallucinogenic alkaloid. It was isolated in 1958 and can be synthesized to nearly 100% purity. The human body is very sensitive to this neurotoxin and just 0.01 g of psilocybin powder contains the equivalent psilocybin found in 30 fresh Psilocybe mushrooms.

For a decade after its isolation, psilocybin, mainly in the form of pills, was readily available in the United States as a pharmacological drug. It was prescribed for psychological therapy. In 1968, psilocybin was made illegal, as few positive conclusions could be drawn about its benefits. Also, it had a high incidence of abuse. Psilocybin powder is usually swallowed, injected intravenously, or sniffed. Due to its high potency, it carries a high risk of overdose. Psilocybin powder or pills are expensive and difficult to produce and therefore difficult to obtain on the street. Studies indicate that when psilocybin is sold on the street, it is usually LSD, PCP (phencyclidine), or both.

Psilocybin liquid

Psilocybin liquid comes from pulverized Psilocybe mushrooms. Archeologists in Central and South America have discovered stones, paintings, and slender tubes depicting the practice of extracting and ingesting the liquid. These paintings date back to a.d. 1. This potent liquid, free from the bulky plant material, is then either swallowed or inserted rectally as an enema. Psilocybin liquid is still consumed by both methods by Mexican natives as part of their religious rites. Due to its potency and especially if it is used rectally, liquid psilocybin carries a high risk of overdose.

Soaking Psilocybe mushrooms in water makes a much less potent psilocybin liquid. This liquid is often drunk as a tea. Psilocybe mushrooms and the liquid are illegal to possess in the United States.

Psilocybin mushrooms

The most common way to access psilocybin is by eating Psilocybe mushrooms. Fresh Psilocybe mushrooms contain 0.03 to 1.3% psilocybin by weight. Dried mushrooms, which can shrink by 90–95%, contain about ten times the amount of psilocybin per weight after the water is removed. The most commonly cultivated or natively collected species are Panaeolus subbalteatus and tropicalis, Psilocybe baeocystis, caerulescens, cubensis, cyanescens, mexicana, pelliculosa, semi-lanceata, stuntzii, and Copelandia cyanescens and cambodgeniensis. The amount of psilocybin in mushrooms varies considerably. Even in controlled laboratory conditions the psilocybin content can vary up to four times from mushroom to mushroom. In nature, mushrooms of the same species and in the same location can contain up to ten times the amount of psilocybin from the highest content to the lowest.

While Psilocybe mushrooms rarely cause death, except in small children, the greatest risk for those who pick their own mushrooms is accidentally ingesting non-Psilocybe poisonous mushrooms. Because mushrooms in one stage of growth can look like mature mushrooms of the desired species, amateurs may pick toxic mushrooms. For users who choose to buy prepicked mushrooms, studies indicate that common grocery store mushrooms are often injected with the much more potent LSD or other drugs and passed off as Psilocybes. The mushrooms are then frozen as a black mass so that their true identity is hidden. Psilocybe mushrooms, which are illegal to possess in the United States, are either eaten whole or ground up into a powder and swallowed.


The amount of psilocybin consumed and the way it is ingested greatly determines the effect it will have on the brain and the body. Since psilocybin is a neurotoxin, the more that is consumed and the faster it reaches the brain, the greater the chance of adverse reactions or overdose.

Mouth and stomach

By far, the most common way to ingest psilocybin is by eating Psilocybe mushrooms. Mushroom eaters generally consider 1–5 g of dried mushrooms or 10–15 g of fresh mushrooms a moderate dose. While some absorption of psilocybin begins in the mouth, the majority of this neurotoxin passes through into the blood stream via the small intestines. The small intestines, having the surface area of a football field, are well suited for absorbing both nutrients and toxins. However, before the psilocybin reaches the small intestines, it must cross the barrier of the stomach. Since psilocybin is a base and the stomach secretes an acid, the absorption rate is greatly slowed. Within a few minutes it is common to feel nausea and many "eaters" of mushrooms vomit. After the psilocybin passes through the stomach and the small intestines, it reaches the blood. Once there, it must pass through the liver before it can get to its intended site—the brain. All of this results in the blood levels of psilocybin gradually increasing over a 30-minute to two-hour time period.

Initially, the user notices a feeling of anxiety or anticipation. As the feeling intensifies, emotions may fluctuate rapidly and tension is released by crying and laughing. Perception of space and time are blurred, and visual images or "hallucinations" often appear. The primary effect lasts four to six hours. Many people find it difficult to sleep and notice that the altered sense of reality persists for an additional two to six hours.

Because the psilocybin alkaloid in the mushrooms is so bitter, many users try to mask the flavor by adding spices, orange juice, chocolate or other strong-flavored foods. Some "eaters" put the mushrooms on pizza or inside omelettes or soup. Finally, some bypass the mushroom flesh altogether by making mushroom tea. After soaking the mushrooms in hot water for about five minutes, they discard the mushrooms and drink the liquid. This results in less psilocybin being ingested, but what is swallowed is more quickly absorbed.

Religious customs using the Psilocybe mushrooms are still practiced by Native Americans in Mexico, the United States, and other places around the world. However, the practice is generally reserved for rare and sacred rituals.


Injecting Psilocybe mushroom juice intravenously is not common but it is reported. Most psilocybin users are seeking a "natural" experience and use of needles is not considered natural. Intravenous injection is the fastest means of getting psilocybin to the brain. In less than 16 seconds, the psilocybin is mixed with the blood, taken to the lungs, returned to the heart, and delivered to the brain. As the natural barriers and buffers of the stomach, small intestine, and liver are bypassed, the chances of overdose and adverse side effects such as coma, convulsions, and kidney failure, are greatly increased. It is even more rare for users to inject psilocybin powder, as this drug is difficult to obtain on the street. Supposed psilocybin powder bought on the street is almost always LSD, PCP, or both.


Injecting psilocybin liquid rectally by means of an enema is second only to intravenous injection for having the drug reach the brain quickly. This area of the body has a significant surface area for absorption. This method reduces nausea and vomiting associated with eating mushrooms. There is no stomach acid to slow the absorption of the psilocybin base. Also, the liver is bypassed as the drug is absorbed into the blood. This method of using psilocybin is uncommon in non-Native American cultures because most users of psilocybin are interested in a "natural" experience and enema administration is not considered "natural" to most users.

Archeological evidence of psilocybin liquid via enemas dates back to a.d. 1 and some tribes still practice this method today. In ancient times, a hollow bone or tube was inserted deep into the rectum. Then an animal bladder filled with the psilocybin liquid was attached to the end of the tube. The liquid was then squirted deep into the rectum and lower intestine. Because so many natural barriers are bypassed by this method, the user is at great risk for overdose, serious side effects, or death.

Smoking and snorting

There are some reports that psilocybin is smoked or snorted but very little information is available. This is not a very common means of ingesting psilocybin.


Psilocybin is an illegal drug with no accepted therapeutic uses. Before 1968, psilocybin was readily available in natural and synthetic forms in the United States. For over a decade, the drug was used in numerous tests to see if it had therapeutic value. One study was done from 1961–63. Timothy Leary and Ralph Metzner attempted to reform criminals at the Massachusetts Correctional Institute in Concord. The inmates were given two high doses of psilocybin over six weeks, along with several sessions of therapy. It was hoped that in the drug-induced state, inmates would confront their inclinations, gain new personal insights, and choose to leave the life of crime. The real test came when the inmates were released from prison. In the final analysis, the psilocybin-subjected inmates had the same rate of return to prison as the inmates who were not part of the study. In addition, they had more parole violations than the general parolees. In numerous other studies, psilocybin was employed to help people with mental and emotional illnesses. Because psilocybin causes shifts in perception and loosens emotions and thoughts, this drug was used to treat neurotic and psychosomatic disorders.

Numerous studies in the 1960s failed to demonstrate that psilocybin has positive and long-lasting benefits for patients. Abuse of psilocybin by the general population was on the rise. In 1968, psilocybin was made illegal. In 2002, there were psilocybin studies underway to see if the drug can be useful in treating obsessive-compulsive disorder or if it can be used as a truth serum. As there is a worldwide trend for increased use of Psilocybe mushrooms, especially among young adults, several studies are underway in Germany and Switzerland to better understand the effects of psilocybin on the mind and body.

Psilocybe mushrooms are still used by Mexican natives in divinatory psychotherapy, which is therapy that focuses on mental and emotional problems. Manuals written in the 1600s detail the use of Psilocybe mushrooms by native shamans for curing virtually every physical ailment. There is no scientific evidence supporting the effectiveness of this ancient religious tradition in curing disease.


Prior to 1957, mainstream Americans had rarely, if ever, heard of psilocybin mushrooms. It was only after pioneering ethnomycologist R. Gordon Wasson published his personal account that people began to take an interest in this mind-altering hallucinogen. His story detailed his experience of eating psilocybin mushrooms during a religious rite with Mexican natives in the Sierra Mazateca. Wasson's publicity took place at a time when the "flower children" and drug culture of the 1960s was just beginning to take root. Thousands of people, ranging from scientists to thrill seekers and hippies, went to Mexico in search of the "magic mushroom." These non-natives did not respect the mushrooms as being sacred. Also, at that time, people did not realize that psilocybin mushrooms grow natively around the world.

Abuse of the psilocybin mushroom continued and clinical studies were finding little evidence that psilocybin mushrooms have medical uses. This trend of increasing "recreational" use of psilocybin was similar to the pattern of drug use in America. In 1962, fewer than 2% of the United States population had tried an illicit drug. By 1979, 65% of high school seniors and 70% of young adults had tried an illicit drug.

In 1968, psilocybin was made illegal. In 1970, in response to the epidemic proportions of drug use, the Comprehensive Drug Abuse Prevention and Control Act was passed. The Controlled Substances Act (CSA) created a schedule for drugs based on their medical uses and the probability of abuse. At that time, psilocybin was placed in the most restrictive category as a Schedule I hallucinogen.

The passing of the Beat Generation of the 1950s and the hippies in the 1960s combined with new findings about the toxicity of psilocybin caused the trend of Psilocybe mushroom use to stabilize and then subside by the 1980s and early 1990s. However, in the mid-1990s, there was a noticeable resurgence in psilocybin mushroom consumption. This is fueled in part by a social trend among young adults to try to recreate the 1960s. In 2002, psilocybin mushrooms are becoming more common at raves, parties, and on college campuses.

Scope and severity

According to the National Household Survey on Drug Abuse (NHSDA), Psilocybe mushroom use is on the rise. In 1997, 10.2 million Americans had tried psilocybin. A study funded by the National Institute on Drug Abuse (NIDA) reported that even though reported psilocybin use is rising, it might still be significantly underreported. One reason for this is that surveys often ask students if they use "psilocybin," which is a scientific term, instead employing slang terms such as "shrooms" or "mushrooms." The study indicated that the underreporting is not a case of students trying to conceal drug use as much as students not understanding the scientific terms in the survey. NHSDA showed that psilocybin use rose most dramatically among the 18–25 year olds. In 1997,7.9% of this population surveyed reported using these mushrooms. Just a year later the figure jumped to 10.9%. This agrees with the U.S. Drug Enforcement Administration's (DEA) reports that psilocybin mushrooms are increasingly found on college campuses, in raves, and in clubs. The Community Epidemiology Work Group (CEWG), which follows drug abuse trends in 21 major metropolitan areas, indicates that psilocybin mushrooms are available in Boston, Baltimore, Minneapolis/St. Paul, and Seattle.

Access to Psilocybe mushrooms is increasing. They grow naturally in the Gulf States and the Pacific Northwest. In other areas across the United States, the mushrooms are cultivated in laboratories or in homes with kits purchased over the Internet. Psilocybin mushrooms in the United States often sell for $20–40 per one-eighth ounce.

Around the world there is a marked and renewed interest in psilocybin. Mushrooms are regaining the popularity they experienced in the 1960s and 1970s. Germany, Poland, Switzerland, and Scandinavia also report increased psilocybin use. In Canada, according to the 1999 Ontario Student Drug Use Survey, psilocybin use has increased significantly from 1997 to 1999. In Great Britain, 785 second-year medical students were surveyed. Seven percent of those surveyed reported using psilocybin. Combining this with other studies, researchers concluded that psilocybin use is increasing among the general university population as well.

In Japan, however, due to a loophole in the law, psilocybin mushrooms can be sold as long as they are not designated for human consumption. They are sold as "aroma pads" or for "decorative uses" and then openly eaten, especially among the college-aged people. Due to this popular trend, the Ministry of Health, Welfare, and Labor is considering making the mushrooms illegal.

Age, ethnic, and gender trends

According to the NHSDA, 18–25 year olds are the fastest growing group of psilocybin mushroom consumers. In one year, from 1997 to 1998, the number of lifetime users (the number of people who have ever used psilocybin in their lifetime) jumped up 38%. The younger age group of 12–17-year-olds remained the stable at 2.6% of the population. The age group of 26–34

indicated a slowing as the figure dropped from 7.9% to7.1%. However, there was another sharp rise in the 35 and older population.

A 1999 NIDA-funded research project at John Hopkins University estimated that 14% of U.S. residents had an opportunity to try hallucinogens, including psilocybin. The vast majority of those who used the drug transitioned from first opportunity to first use within one year. The study indicates that the probability of making this transition is increasing, especially for hallucinogens. This study indicates that the age of first use is directly related to the age of first opportunity. Race and ethnicity is a factor in hallucinogen use. This is especially apparent in 18–25-year-olds, a category in which whites were more than 10 times as likely to report lifetime hallucinogen use as blacks. In this same age group, Hispanic use of hallucinogens was also greater than that of blacks. This relationship exists for all age groups surveyed except in the two older age groups (26–34 and 35 and older). In this case, there was no difference in reported lifetime use between Hispanics and blacks. In the adult age groups, males were twice as likely as females to report lifetime and past-year use of hallucinogens. In the age group of 12–17, there was no significant gender difference. The 1999 NIDA-funded research project at John Hopkins University indicated that males have more opportunities to try hallucinogens, but were not more likely than females to progress to actual use once the opportunity presented itself. Research done by the National Poison Control Center determined that women in its survey at raves in the Unit ed Kingdom reported a higher consumption of psilocy bin than men.

There is no single predictor of psilocybin use. Since the mid-1990s, psilocybin mushrooms have gained broader acceptance as a "natural" hallucinogen. Young people, especially the rave crowd, misinterpret a "naturally" occurring drug as a "safe" drug. Many are unaware of the adverse side effects that can come from an over-dose, repeated use, or even a single exposure. The more a person views a drug as socially acceptable or safe, the more likely that person is to use the drug. Additionally, availability greatly affects a person's decision to use. Psilocybin is now easily accessible for 18–25-year-olds who attend colleges and rave clubs. Generally, psilocybin is not the first drug that is tried by a person. Usually, alcohol, tobacco, and marijuana, which are more readily available and more socially acceptable, are tried first as "gateway drugs." Finally, family and friends can influence a person's decision to use psilocybin. According to the National Poison Control Center, psilocybin was accessed through friends more than any other source.


Small doses of psilocybin mushrooms cause the user to feel relaxed. Moderate doses, which are generally 1–5 g of dried mushrooms or 10–15 g of fresh mushrooms, first cause of a feeling of tingling throughout the body, followed by a feeling of anxiety, anticipation, or alarm. It takes 30–60 minutes for the psilocybin to begin to take effect. As the effect of the drug heightens, users will experience mood swings from depression to joy and from euphoria (a feeling of well being) to fear. Perception of time, space, and the user's own body is altered. Time usually seems to slow down. However, sometimes users believe time is standing still, winding backwards, or freezing in place. As hallucinations take on a visual form, users can feel as though the walls are breathing. Small and previously insignificant details can take on a new and profound meaning. Colors can take on brilliant and dazzling shapes such as tunnels/funnels, spirals, lattices/honeycombs, and cobwebs. Synesthesia or "crosswiring" of the brain's chemical circuitry can cause sound to be felt or seen and colors to be heard or tasted. Boundaries are often distorted and suddenly one's hand may seem like it is several yards away, or shriveled, or shrunken to the size of an infant's hand.

It can be a short step from intrigue to panic. Psilocybin users can have "bad trips" where they may believe they are sinking into the floor or they are being suffocated or harmed by others. The primary effects of psilocybin last four to six hours. For an additional two to four hours many users find it difficult to sleep and continue to experience an altered reality. It is common within the next few days to experience mood swings. Also, due to the intense nature of the experience, it is common to have recurring thoughts or feelings for several days or weeks.

Though psilocybin is known as a "natural" hallucinogen and has a reputation of being gentler than LSD, it is still known to cause panic attacks, "bad trips," and to precipitate mental illness in some people. In 1998, a study at the Psychiatric University Hospital in Zurich, Switzerland, demonstrated that psilocybin produces a psychosis-like syndrome in healthy humans that is similar to early schizophrenia. The study showed that psilocybin-induced psychosis was due to serotonin-2A receptor activation and was not dependent on dopamine stimulation.


Psilocybin is a neurotoxin that bears close resemblance to the human brain neurotransmitter serotonin. Psilocybin is a specific central nervous system (CNS) serotonin (5-HT) receptor activator. It causes disruption in the normal serotonin levels in the brain. This disruption causes dilated pupils, a feeling of numbness throughout the body, nausea, blurred vision, exaggerated reflexes, tremors, loss of appetite, sleeplessness, and hallucinations. It also causes an increase in body temperature, blood pressure, and heart rate. A large amount of psilocybin, or psilocybin ingested by people with sensitivities to the drug, or by small children, can cause seizures, coma, and death. Ingesting psilocybin also interferes with the transmission and processing of external stimuli. The most common reasons for people who have ingested psilocybin to go to the hospital are hallucinations, hyperexcitability, panic attacks, coma, and convulsions.

Psilocybin is not considered to be addictive. However, there is a high risk of tolerance that leads to increased doses. Tolerance occurs when a person repeatedly uses psilocybin in a short period of time. The user's body will change the way it processes the drug. To recapture the effect from an earlier use, the person experiencing tolerance would have to use increasing amounts of the drug. Using psilocybin more often and in larger quantities increases the chances of experiencing serious side effects requiring medical attention.

Psilocybin is activated in the body by first being converted to psilocin by the enzyme alkaline phosphatase. Psilocin is then metabolized and inactivated by monoamine oxidase to form 4-hydroxyindole-3-acetic acid. This is then excreted in the urine.

Harmful side effects

The most common harmful side effect from ingesting psilocybin mushrooms is a panic attack caused by a "bad trip." A "bad trip" is often described as terrifying hallucinations, unwanted thoughts, frightening visions, serious distress, and paranoia. Some reported "bad trips" include hallucinations of skin turned to liquid, worms crawling inside the users body, sinking into the ground, or being suffocated by someone. In a 2000 study that examined 161 acute psilocybin mushrooms exposures reported to the Swiss Toxicological Information Center (STIC), 31% of the users were admitted to the hospital for panic attacks. The loss of self-control, aggressive response to others, and general psychosis generally lasts fewer than 24 hours, though long-term side effects are possible. Panic attacks and "bad trips" are not preventable or predicable, and often happen to users who have experienced "good trips" in the past.

Other reasons listed for hospitalization of Psilocybe mushroom users are hallucinations, hyperexcitability, tachycardia (excessively rapid heart rate), incontinence of urine, coma, and convulsions. Severe complications arise when users mix psilocybin with other drugs such as alcohol, opioids, or LSD. The International Programme on Chemical Safety Poisons Information Monograph (INCHEM) on fungi reports that some people are allergic to psilocybin mushrooms with fatal results. Others accidentally ingest poisonous mushrooms, which results in serious adverse side effects or death. Users who have ingested mushrooms several days consecutively or who are sensitive to other naturally occurring substances in the mushrooms such as phenylethylamine can experience serious heart problems.

Overdoses of psilocybin may cause intense side effects that require medical attention. Overdoses can happen easily because there are over a dozen common species of Psilocybe mushrooms, and one mushroom of one species can have the equivalent potency of 20 mushrooms of another strain. Also, because LSD is usually cheaper than Psilocybe mushrooms, grocery store mushrooms are often injected with LSD and then sold as Psilocybe mushrooms. As LSD is 100 times more potent than psilocybin, this greatly increases the chances of an overdose.

When unsuspecting individuals accidentally ingest psilocybin mushrooms, it is common for them to conclude that they are going insane because of the hallucinations and psychosis that occurs.

The effect of psilocybin on pregnant women is not known yet. In studies of LSD, which has a similar structure to psilocybin, it has been shown that large doses can cause spontaneous abortion. Studies also indicated increased risk for birth defects, such as malformed limbs, heart defects, and eye lens defects associated with LSD use during pregnancy. Central and South American natives have used psilocybin for thousands of years, but generally this was done during rare religious rituals and usually women and children did not partake. Therefore, this history offers little insight to the effects of psilocybin during pregnancy.

Long-term health effects

Ingesting Psilocybe mushrooms has been known to precipitate long-term mental illness including paranoia, depression, and psychosis. It is uncertain as to whether the user would have eventually developed these conditions in the absence of psilocybin. However, there does appear to be an increased risk of developing chronic mental problems after the use of psilocybin if the user has a family history of mental illness.

Another long-term side effect is called flashbacks. Flashbacks are recurrences of the drug's effects when the drug is not being used. Sometimes several months after last use, persons who ingested Psilocybe mushrooms will unexpectedly experience hallucinations or mood swings. Often flashbacks occur when the past user is tired, anxious, uses another drug, or moves from a lighted environment into a dark one. Over 15% of people who use psilocybin experience this delayed effect. Users unaware of this side effect have sometimes sought medical attention fearing they were going insane.

Long term and sometimes lethal side effects also come in the form of self-inflicted injuries due to poor judgement while under the influence of psilocybin. As sensitivity to pain is decreased, the users may not know they are hurting themselves until later. In other instances, the users can overestimate their abilities and attempt something like trying to jump from extreme heights or walk on water. Occasionally, users under the influence of psilocybin become distressed to the point of committing suicide.


Combining psilocybin with other drugs greatly increases the risk of having adverse side effects requiring medical treatment. Sometimes drugs are unintentionally combined. This happens to people who are taking monoamine oxidase inhibitors (MAOIs) which are commonly found in some antidepressants. Combining MAOIs and psilocybin can dramatically increase the effect of the psilocybin. On the other hand, users often purposely combine psilocybin with other drugs. Combining psilocybin with MDMA (methylenedioxymethamphetamine, commonly known as ecstasy) is known as a "hippy flip" or "MX-missile." This combination greatly intensifies the effects of psilocybin and likewise greatly increases the chances of serious side effects.

In a 2000 study which examined 161 acute psilocybin mushrooms exposures reported to the Swiss Toxicological Information Center (STIC), researchers noted that severe complications from psilocybin use were most likely to occur when it was combined with other drugs such as opioids, alcohol, or LSD. Some of the severe complications listed in the study were coma and convulsions.


While there is no antidote or antitoxin available to halt a panic attack brought on by ingesting psilocybin, the trauma can be minimized by placing the patient in a room with dim lights, giving reassuring encouragement to the patient, and using sedatives. According to the International Programme on Chemical Safety (INCHEM) poisons information monograph on fungi, in the case of psilocybin poisoning (whether intentional or not) the hospitalized patient may be given diazepam. Diazepam is also recommended if the patient develops psilocybin-induced seizures. The INCHEM report indicates that most psilocybin-induced side effects are short (less than 24 hours) and uncomplicated. The main threat to the patient and to the hospital staff is violent and uncontrolled behavior.

Psilocybin is not physically addictive. This drug is rarely the only drug of use by people seeking rehabilitation. So admissions into rehabilitation centers remains low for psilocybin. A 1999 study in Russia involving 180 young patients who used psilocybin mushrooms reported that they also used other "natural" drugs such as amanita and datura. In the treatment program, patients were educated about the toxic basis of these drugs. Likewise, a 1999 NIDA-funded study research indicated that rehabilitation programs for young people should include information on the function and toxicity of the drugs, self-control training, and methods for managing anger and impulsiveness.

A popular program for treatment and rehabilitation of psilocybin and other drug use is Narcotics Anonymous (NA). This is a 12-step program that includes admitting there is a problem, seeking help, making amends, and helping others. There are no dues or fees and meetings are held in virtually all major cities in the United States and in 113 countries. In keeping with the explosion of drug use in the United States since the early 1960s, NA's registered groups have gone from 200 in 1978 to over 19,000 in 2001.


One of the most significant personal consequences of psilocybin use is self-inflicted injury. During an euphoric or "good trip" users can overestimate their abilities and use poor judgement. There are reports of users trying to drive a car, standing in front of a moving vehicle, trying to walk on water, or jumping out of high places. Such feats have resulted in life-long injuries and in some cases, death.

On the other end of the spectrum, harm is done to others when users experience fear and panic attacks from "bad trips" or frightful visions. Users have been known to attack their family, friends, or medical staff while under the delusion that such ones were trying to harm them. Though the effects of psilocybin rarely persist after 24 hours, the results of poor judgement can last a lifetime. Also, people convicted of psilocybin possession can be disqualified from obtaining federal college grants and loans.

According to the 1999 Ontario Student Drug Use Survey, researchers note that substance abuse disorders account for the most prevalent mental health conditions in young people. As the abusing population increases, so will future clinical needs of this population. Psilocybin use can precipitate long-term mental illness.


Under the Controlled Substance Act, psilocybin is a Schedule I drug. This means that psilocybin has a high potential for abuse, has no accepted medical use in the United States, and lacks acceptance as being safe for use under medical supervision. Schedule I drugs are subject to the tightest controls. While Psilocybe mushrooms are not specifically listed in the federal law, the two primary psychoactive chemicals, psilocybin and psilocin, are listed. Because the substances are illegal to possess, so are the fresh and dried mushrooms. Cultures at the mycelium stage when psilocybin becomes present and cultures at the mushroom stage are also illegal. Because spores do not contain psilocybin, they are legal according to federal law. However, at least one state, California, has passed a law making spores illegal to possess.

Legal history

For thousands of years Native Americans in Central and South America have used Psilocybe mushrooms in rare and sacred religious rites and ceremonies. Today, natives in these countries and in the United States use psilocybin legally in practicing their religion. Non-native Americans were not aware of the hallucinogenic effect of Psilocybe mushrooms until 1957, even though they grow naturally in many parts of the country. But in 1957, a researcher published his personal experience of eating Psilocybe mushrooms during a religious rite in Mexico. His favorable account was printed in the popular Life magazine. This account brought a great deal of interest to the Psilocybe mushrooms.

Though there was virtually no scientific research done on the drug's side effects prior to the magazine's story, over the next decade thousands of Americans and Europeans were willing to experiment with mushrooms. Scientists, psychologists, and researchers also started experimenting with synthetic psilocybin and Psilocybe mushrooms. As use of psilocybin increased, scientists began to see that the drug had few probable medical uses and had a high potential for abuse.

Psilocybin was legal in the United States for about a decade, but in 1968 it was made illegal. In 1970, in response to the epidemic proportions of drug use, the Comprehensive Drug Abuse Prevention and Control Act was passed. The Controlled Substances Act (CSA) listed psilocybin as a Schedule I hallucinogen, which is the most restricted drug category.

In 2002, psilocybin is once again gaining popularity. It is found at raves, on college campuses, and in clubs. Psilocybe mushroom seizures at raves are becoming more common. In the past, policing efforts were more difficult because if mushrooms were ground to a powder it was difficult to identify them as Psilocybe mushrooms. A new DNA test for mushrooms has helped solve this problem. Also, Psilocybe mushrooms are fairly easy to cultivate. In 1999, Orange County, California law enforcement officers seized Psilocybe mushrooms valued at one million dollars from a college student's apartment. As the spores are not illegal except in a few states such as California, they are fairly easy to access. But once the spores become mycelium or mushrooms, they are illegal to possess. This little window of "legal" status makes law enforcement more difficult.

The United Nations standard on psilocybin allows for possession of fresh mushrooms, but not dried mushrooms. Most countries that are members of the United Nations follow this standard. However, Japan allows dried mushrooms to be sold legally.

Federal guidelines, regulations, and penalties

The Anti-Drug Abuse Act of 1986 and 1988 set forth federal mandatory minimum sentencing guidelines. According to the Federal Trafficking Penalties, first offense penalties for anyone who manufactures, dispenses, distributes, or possesses psilocybin is imprisonment for up to 20 years. If a death or serious injury is involved there is a mandatory minimum sentence of not less than 20 years, but not to exceed a life sentence. Individuals can also be fined up to one million dollars. In the case of a second offense, offenders can receive up to a 30-year prison sentence. If a death or serious injury is involved, there is a mandatory minimum life sentence. Individuals can also be fined up to two million dollars.



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U.S. Food & Drug Administration Center for Food Safety & Applied Nutrition Foodborne Pathogenic Microorganisms and Natural Toxins Handbook. Chapter 40. Psilocybin Poisoning.<>.


Narcotics Anonymous (NA), P.O. Box 9999, Van Nuys, CA, USA, 91409, (818) 773-9999, (818) 700-0700, <>.

Patty Jo Sawvel