Psilocybin is a hallucinogen found in certain varieties of mushrooms that grow around the world. Effects include enhanced senses, distortion of time and space, feelings of detachment, and visual disturbances. Some of these experiences can be frightening and are referred to as “bad trips.” Most users do not become addicted to mushrooms, but they can develop tolerance.
Researchers are studying psilocybin to see if it can treat mental health disorders such as anxiety, depression, and addiction.
What Are Psilocybin Mushrooms?
Psilocybin mushrooms, or “magic mushrooms,” are fungi that contain the hallucinogenic compounds psilocybin and psilocin.1
Psilocybin and psilocin are found in more than 75 species of mushrooms that are native to tropical and subtropical areas of South America, Mexico, Southeast Asia, Europe, and the United States.2 The two most common species used in the United States are Psilocybe mexicana and Psilocybe cyanescens.6
Psilocybin is a Schedule I drug in the United States, which means it has no accepted medical use and a high potential for abuse.4
- Las mujercitas.
- Little smoke.
- Magic mushrooms.
- Silly putty.
- Simple Simon.1,2
Use of magic mushrooms goes back more than 2,000 years to natives in Central America. Statues of mushrooms have been found in Guatemala that date back to around 100 B.C. The Aztecs also reportedly used mushrooms during some of their ceremonies. When the Spanish arrived in Mexico in the 1500s, the natives referred to one mushroom species, Psilocybe mexicana, as “God’s flesh.”3
Mushrooms came into popular culture in 1957, when a banker and mushroom enthusiast named R. Gordon Wasson discovered a tribe in Mexico using psychedelic mushrooms while he was on vacation. He sent a sample to Albert Hofmann, the Swiss chemist who synthesized LSD. Hofmann isolated psilocybin and began to produce pills to be used in research. LIFE magazine published a photo essay on Wasson, which attracted attention.5
Psilocybin was used in research studies for the next two decades. The research focused on psychiatric conditions such as alcoholism, schizophrenia, autism, obsessive-compulsive disorder, and depression. Professor Timothy Leary also conducted psilocybin experiments at Harvard. In 1968, mushrooms were made illegal because of widespread abuse.2,3,5
In the 1960s, Harvard professor Timothy Leary conducted an experiment at Harvard where he gave 20 theological students either a placebo or psilocybin. The study was double-blind, which meant neither Leary nor the students knew who had taken the drug. They all attended the Good Friday religious service, where the group that took the drug reported mystical experiences.3
How Do People Use Them?
Fresh or dried mushrooms are often eaten raw or boiled in water to drink as a tea. Some people prepare them with food to hide their taste. They can also be crushed into a powder and put into capsules, tablets, or solutions.1,2
A typical recreational dose is 1-5 grams of dry mushrooms based on the species and potency of the mushroom. Dosages for fresh mushrooms are about 10 times higher (10-50 grams).1
One of the hazards of mushrooms is mistakenly consuming the wrong kind of mushroom. It can be difficult to identify mushrooms in the field, and poisonous mushrooms can also cause hallucinations and even death.6,7
Home test kits that claim to be able to identify psilocybin mushrooms may not be 100% accurate, and it can be difficult to pin down the exact kind of mushroom spore from a mail-order service.6
Another risk is ingesting ordinary store-bought mushrooms that are laced with LSD or PCP.8
What Are the Effects?
Several factors can influence the effects of mushrooms, including:2,8
- User expectations.
- Physical and emotional health.
- Prior drug experiences.
- Age, type, and amount of mushroom taken.
The user’s mindset and environment can vary, which means each experience on the drug, or “trip,” can be different.5
Effects generally begin within 20 minutes to 2 hours after ingesting the drug and last 3 to 6 hours.2
- Abdominal cramps.
- Poor coordination.
- Dilation of pupils.
- Dry mouth.
- Increased heart rate and blood pressure.
- Increased body temperature.
- Sensory enhancement.
- Hallucinations of sight, sound, and touch (i.e., moving surfaces, waves).
- Trouble thinking clearly.
- Focus on trivial thoughts or objects.
- Feeling of detachment from body and the environment.
- Distortion of time and space.
- Difficulty distinguishing fantasy from reality.
- Spiritual experiences.
Potential long-term effects of mushrooms include flashbacks, and impaired memory, and an increased likelihood of certain psychiatric issues.9 Psilocybin and other hallucinogens can trigger or exacerbate conditions such as schizophrenia, mania, and depression.7
Two after-effects of hallucinogen use have been studied: persistent psychosis and hallucinogen persisting perception disorder (HPPD). These are not common, but it is hard to know who will experience them and when. They are usually observed in people with a history of mental health problems. But they can happen to anybody-even people who only use these drugs once.10
Symptoms of persistent psychosis include:10
- Visual distortions.
- Disorganized thinking.
- Mood shifts.
Symptoms of HPPD include re-experiencing symptoms from hallucinogen use after the effects of the drug have worn off. These include seeing geometric shapes, false sense of movement in peripheral vision, color flashes, trails or halos on objects, and the perception that objects are larger or smaller than normal. These signs, often called “flashbacks,” can last for weeks, months, or years.11
Flashbacks are most common in LSD users, but they have been reported in people who use other hallucinogens. They may be more likely to occur in people who use hallucinogens repeatedly.6
In people experiencing HPPD, antidepressant and antipsychotic drugs have been used to help with mood and psychotic symptoms. Psychotherapy has also been shown to help some users deal with the anxiety of flashbacks.10
What Are ‘Bad Trips’?
A “bad trip” is when a mushroom user feels intense anxiety and panic while on the drug and fears he or she will go insane or even die. They may have frightening hallucinations and feel confused, disoriented, paranoid, or depressed. The user may fear that they will not be able to come back from the trip, and the memory of the experience may remain with them for a long time.2,6,7,10
If you or someone you know has a bad trip, you can take the following steps:7
- Get to a place where you or the person feels safe and comfortable.
- Remove any kind of visual stimulation or noise.
- Speak to the person in a calm and reassuring voice and let them know that whatever they are feeling is just the effects of the drug, and it will wear off with time.
- If the person becomes violent or cannot calm down, seek medical help.
The effects of a bad trip will usually go away as the drug wears off. In severe cases, anxiety can be treated with benzodiazepine drugs such as Valium.6
A global survey in 2014 found that Canada and the United States were the most common countries where users reported a bad trip on mushrooms. Almost 34% of Canadian respondents said they’d had a bad trip, and 32% of Americans reported the same. Portuguese and Brazilian users were the least likely to report a bad trip, at 12% and 12.5%, respectively.12
Are Mushrooms Addictive?
Psilocybin and other hallucinogens such as LSD are generally not considered addictive. They do not usually lead to compulsive use or drug-seeking behavior like other drugs, and users do not typically become physically dependent.6,7 Withdrawal symptoms are not known to occur if a heavy user stops taking mushrooms.10
Possible explanations for the lack of addiction with these drugs is that they don’t activate pleasure centers in the brain like stimulants and opioids. The effects can also be so mentally and physically intense that users limit their use.5,6
People who regularly use mushrooms, however, can develop a tolerance to them. This means that the subjective effects of the drug will diminish when someone takes similar doses of the drug repeatedly over time. Additionally, frequent mushroom users may build tolerance to other hallucinogens that act on the same brain receptors, such as LSD and peyote. This tolerance does not last, though, if the person abstains for several days.10
Hallucinogen Use Disorder
Despite the lack of addictive potential of mushrooms, some people develop a pattern of consistent use that resembles addiction. Polydrug addicts, for example, may abuse mushrooms with other drugs such as alcohol or marijuana.7
The Diagnostic and Statistical Manual of Mental Disorders lists the criteria for hallucinogen use disorder, which is the clinical term for a “hallucinogen addiction.” Some of the symptoms of this condition include:11
- Spending more and more time acquiring hallucinogens, using them, and recovering from their effects.
- Feeling cravings to use hallucinogens.
- Engaging less in social, occupational, or recreational activities in favor of hallucinogen use.
- Continuing to use hallucinogens even though the person has a physical or psychological problem related to hallucinogen use.
- Using hallucinogens even though this drug use interferes with responsibilities at work, school, or home.
- Trying but being unable to cut down or control hallucinogen use.
- Developing a tolerance to hallucinogens.
If you or someone you know shows some of these signs, consider some form of professional treatment, such as a rehab program, counseling, or a 12-step group.
Can You Overdose?
Lethal doses of mushrooms have been observed in animal studies, but overdose deaths caused solely by usual doses of mushrooms are rare. The drug is considered to have low toxicity.5
However, there is a psychological risk from consuming too much psilocybin. Larger doses can lead to longer, more intense trips, and possibly psychosis.4
As mentioned above, another danger is taking what someone thinks is mushrooms but is actually another drug, such as LSD. This situation can also lead to a bad reaction.
How Many People Use Them?
- In 2015, 9.3% of those age 18 and older had used mushrooms at some point in their lives. In 2014, that number was 9.2%.
- In 2015, 1.1% of youth ages 12-17 had used mushrooms at some point in their lives. In 2014, that number was 1%.
- In 2015, 9.3% of those age 18-25 had used mushrooms at some point in their lives. In 2014, that number was 9%.
Can They Be Therapeutic?
The Drug Policy Alliance notes that studies in the mid-20th century found that psilocybin may be able to help people with certain psychological disorders and aid in spiritual development. But these studies stopped after the drug was banned in 1970. Many of them were also flawed because they did not use a control group or double-blind procedures.5
Researchers began studying psilocybin again in the late 1990s and early 2000s. The focus of modern research is whether psilocybin and other psychedelics can help treat conditions such as headaches, anxiety, addiction to alcohol and other drugs, depression, post-traumatic stress disorder, and obsessive-compulsive disorder.1,5
Because psilocybin is a Schedule I drug, much of the funding for these studies comes from nonprofit organizations instead of academic or government institutions.5
The video below features a cancer patient who participated in a study in which she took psilocybin to treat depression and anxiety. About 60% to 80% of the 80 patients in the study showed reductions in both conditions.14
- European Monitoring Centre for Drugs and Drug Addiction. Hallucinogenic mushrooms drug profile.
- University of Maryland Center for Substance Abuse Research. Psilocybin/Psilocyn.
- Hanson, G., Venturelli, P., and Fleckenstein, A. (2017). Drugs and Society. Jones & Bartlett Learning.
- Drug Enforcement Administration. Drugs of Abuse: 2015 Edition: A DEA Resource Guide.
- Drug Policy Alliance. (2017). Psilocybin Mushrooms Fact Sheet.
- Kuhn, C., Swartzwelder, S., Wilson, W. (2014). Buzzed: The Straight Facts About the Most Used and Abused Drugs from Alcohol to Ecstasy, 4th Edition. New York, New York: W. W. Norton & Company.
- Brown University. Psilocybin (Mushrooms).
- Columbia University. Go Ask Alice: Psilocybin (‘magic’) mushrooms.
- National Institute on Drug Abuse. (2009). Hallucinogens: LSD, Peyote, Psilocybin, and PCP.
- National Institute on Drug Abuse. (2015). How Do Hallucinogens (LSD, Psilocybin, Peyote, DMT, and Ayahuasca) Affect the Brain and Body?
- American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders, 5th ed. Arlington, VA: American Psychiatric Publishing.
- Arnett, G. (2014). How bad trips on LSD and magic mushrooms compare. The Guardian.
- Center for Behavioral Health Statistics and Quality. (2016). Results from the 2015 National Survey on Drug Use and Health: Detailed Tables. Substance Abuse and Mental Health Services Administration, Rockville, MD.
- Lapook, J. (2016). Hallucinogenic drug found to help cancer patients fight anxiety, depression. CBS News.