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Psilocybin: Safety, Side Effects & Types of Mushrooms

Written by Ana Aleksic, MSc (Pharmacy) | Last updated:
Puya Yazdi
Medically reviewed by
Puya Yazdi, MD | Written by Ana Aleksic, MSc (Pharmacy) | Last updated:

Psilocybin is a naturally occurring psychedelic substance produced by psilocybin mushrooms, also called ‘magic’ mushrooms. With the modern revival of psychedelic research, psilocybin is being investigated for its potential to help people overcome depression and anxiety. Read on to learn about the history of its use and the intriguing current research.

What is Psilocybin?

Mysterious Psychedelic

Psilocybin (chemically known as 4-phosphoryloxy-N, N-dimethyltryptamine) is a classic psychedelic that belongs to the group of hallucinogenic tryptamines. But the story about psilocybin indigenous use and modern research over the past century is anything but classic [1].

Over 100 species of hallucinogenic “magic” mushrooms contain psilocybin (including Psilocybe, Conocybe, and Paneolus). These mushrooms grow in different parts of the world and have been used ritually for at least 3000 years [2, 1].

Despite the recent renaissance in psychedelic research, there is a lot of controversy surrounding psilocybin use, legal status, and its potential therapeutic effects. Not many people know the whole story behind the traditional use of psilocybin-containing mushrooms, nor about the efforts that produced our current state of knowledge about it.

Psilocybin is a natural psychedelic found in psilocybe mushrooms, also called “magic” mushrooms. Modern research is catching up with their age-old traditional use, surrounded by mystery and controversy.

The Story Of Magic Mushrooms


The first use of hallucinogenic mushrooms dates back about 3,000 years to Mexico. They are still used by native people in some areas for religious ceremonies and healing, although the local communities encountered many struggles in the past.

Shortly after the European conquest of these territories, magic mushrooms were banned for the first time in the early 17th century [2, 3, 4].

A couple of centuries passed before these mushrooms gained the attention of Western scientists and doctors for the first time. Robert Wasson, an American ethnomycologist, popularized these mushrooms in the 50s after returning from an expedition to Mexico where he participated in an indigenous Mazatec religious ritual.

He was one of the first Westerners to participate in such a ritual. He published an article in the Life magazine called “Seeking The Magic Mushroom” in which he described his experience [5].

The article became extremely popular, especially in the counterculture movement of the time, and led many people to travel Mexico seeking to experience the same. But this only brought devastation and unwanted attention from foreigners and police to the local community.

Luckily, it also brought some attention from the scientific community. Psilocybin was first isolated, identified, and synthesized by Albert Hofmann, the “father of LSD”, in the late 50s (from P. mexicana). He later summarized his thoughts about psychedelics, including LSD and psilocybin, in the book “LSD – My Problem Child” [6, 7].

Native Americans have used magic mushrooms in religious and healing rituals for ages. They got introduced into western science in the 50s.

The 60s and 70s

In the 60s, psilocybin research boomed with over 1,000 studies published. It was used in both experimental research and psychotherapy [8].

Some scientists thought that psychedelics like psilocybin modeled “madness” and schizophrenia. Others were investigating its effects on creativity, cognition, and mystical experiences. Many key figures, including Timothy Leary, the British writer Aldous Huxley, and even Allen Ginsberg were involved in these experiments.

It didn’t take long for psilocybin to become popular among the general public as a recreational drug. The name of the band “The Doors” was inspired by Aldous Huxley’s book “The Doors of Perception”, in which he describes his own theories and experiences with psychedelics.

As recreational use got out of hand, psilocybin and other psychedelics were soon banned in the 70s and classified as Schedule I drugs (the same class as heroin). This group of drugs contains substances considered to be the most dangerous for human health and with the highest potential for abuse [6].

Psychedelic research became marginalized, funding was cut, and all human experiments came to a halt [1].

Psilocybin research and recreational use boomed in the 60s. It was banned and classified as a Schedule I drug in the 70s, which halted psychedelic research.

Modern Revival

In the late 1990s, scientists started looking into psilocybin once again. Psychedelics research was revived, and the number of scientific publications is now increasing every day [6].

Although psilocybin remains classified as a Schedule I drug (and is therefore illegal to use and very difficult to study), scientists have become intrigued by its therapeutic potential [6, 1].

Recently, the FDA approved a clinical trial of psilocybin for treatment-resistant depression, which will be conducted in 2019. It will be the largest ever clinical trial of “psychoactive care” — the combination of psilocybin and psychological support.

It’s possible that psilocybin may be approved for depression or other conditions in the future, but it’s still too early and uncertain to say.

The late 90s brought a revival of psilocybin scientific research and interest. Large clinical trials to investigate its therapeutic and antidepressant effects are on the way.

Mechanism of Action

As a classic psychedelic, psilocybin causes hallucinogenic effects by activating specific serotonin receptors: 5-HT2A. It also slightly activates dopamine pathways in the brain and the sympathetic, fight-or-flight system in higher doses [1, 6, 9].

Psilocybin probably achieves long-lasting effects on the brain and its plasticity by changing gene expression, a result of activating 5-HT2A receptors [10].

Ego Dissolution

The key to understanding its mechanism may lie in parts of the brain it affects.

In brain imaging studies in 15 healthy volunteers, psilocybin decreased connectivity in the brain’s default mode network. This system is activated when a person is thinking about oneself, the past, and the future. Meditation also reduces activity in this system [11, 12, 1].

What’s common to both meditation and psychedelic experience is the focus on immediate experience as a dissolution of the sense of self or “ego.”

In the brain imaging study, psilocybin led to so-called “unrestrained cognition.” This resembles the sudden opening of a “valve” that otherwise keeps normal consciousness in check to a more fluid, hyperconnected state [13].

Aldous Huxley first envisioned this valve as something that restricts consciousness but is necessary to maintain biological functions and a sense of self in everyday life. Experiences that occasionally loosen it open up the doors of perception, according to him.

This is also what some refer to as a “resetting” of the brain by psilocybin, which may be necessary for its therapeutic effects. It may explain why the effects of psilocybin persist long after a single use, since brain networks may continue to rearrange themselves after the experience [1].

Psilocybin induces hallucinations via serotonin 5-HT2A receptors. It “rewires” the brain, dissolves the sense of self or ego, and alters perception and consciousness.

Sensory Changes

In another brain imaging study with 7 volunteers, psilocybin (0.25 mg/kg, oral) intensified emotions and sensory perception, caused difficulty concentrating, dreaminess, and a loss of ego boundaries [14].

The sensory changes ranged from illusions to complex scenery hallucinations. Most of them also experienced heightened mood or euphoria. The effects peaked after 30-40 minutes, started to decline after 2 hours, and completely subsided after about 6 hours.

Altered State of Consciousness

Some think psilocybin is very useful for understanding the very nature of human consciousness. In a study of 8 healthy people, psilocybin was given at different doses – from very low (45 μg/kg) to high (315 μg/kg). With higher doses, psilocybin induced a more intense consciousness shift, marked by [15]:

  • Oceanic boundlessness, euphoria, and depersonalization
  • Ego dissolution, which may provoke anxiety
  • Visual hallucinations and synesthesia (mixing of the senses)
  • Dreaminess and reduced alertness

The blurring of the boundaries between self and environment was generally experienced as “touching” or “unifying with a higher reality”. Medium and high doses caused hallucinations, while the lower doses only caused some changes in perception. Only one person in the high-dose group experienced anxiety [15].

Psilocybin triggers sensory changes and intensifies emotions. Higher doses can cause ego dissolution, full-blown hallucinations, and the sense of oneness with the universe.

Psilocybin Content in Mushrooms

Psilocybin content in dried mushrooms varies from 0.2-1% [2].

In research, pure psilocybin pills or intravenous injections are given. Recreationally, people take psilocybin by eating raw or dried hallucinogenic mushrooms, alone or mixed into beverages.


In clinical studies, the effective oral dose was 10-30 mg/70kg or 0.045-0.429 mg/kg, and 1-2 mg per adult intravenously. The minimal dose for psychedelic effects was 15 mg orally. And when it comes to the current research, safety guidelines state that high oral doses of psilocybin are >25 mg [6].


If taken orally, psilocybin converts to psilocin, its active form, in the liver. Psilocin then enters the bloodstream and reaches the brain [16].

How Long Do the Effects Last?

The effects peak after 1-2 hours and last for 4-6 hours after oral use. All the effects wear off after 6-8 hours, even after high psilocybin doses, according to several studies in healthy volunteers [14, 15].

Dry mushrooms contain 0.1-1% of psilocybin. The effective dose is 10-30 mg/70kg, and the effects last for 4-6 hours. The liver converts psilocybin into active psilocin.

Types of Psychedelic Mushrooms

There are over 100 species of psychedelic mushrooms, but the best-known ones are [6, 1]:

  • Psilocybe azurescens (highest psilocybin content)
  • Psilocybe bohemica (second highest psilocybin content)
  • Conocbe cyanopus
  • Copelandia cyanescens
  • Panaeolus africanus
  • Panaeolus subbalteus
  • Inocybe aeruginascens
  • Psilocybe cubensis
  • Psilocybe cyanescens
  • Psilocybe mexicana
  • Psilocybe semilanceata
  • Psilocybe tampanensis

Psilocybin vs LSD or Mescaline

In terms of psychedelic effects, psilocybin is:

  • 45 times less potent than a similar weight of LSD, and
  • 66 times more potent than a similar weight of mescaline

The effects of LSD last much longer, though, sometimes up to 15 hours [17].

Psilocybin Side Effects

Clinical Trials

Given in a supportive, controlled, psychotherapeutic environment, psilocybin does not cause any serious adverse effects [1, 18].

Higher doses of psilocybin are more likely to cause anxiety or fear due to feelings of ego dissolution or lack of control [1].

In one trial of 18 people, higher doses caused the following [19]:

  • 39% experienced extreme fear, fear of insanity or felt trapped
  • 44% reported delusions or paranoid thinking

Ultimately, nobody reported a decrease of wellbeing or life satisfaction from the overall experience.

Other adverse effects that occurred in clinical studies include [1, 18]:

  • Dizziness
  • A slight increase in blood pressure or heart rate
  • Unusual body sensations
  • Mood changes
  • Fatigue and yawning
Psilocybin was safe in a supportive, controlled environment. It may cause dizziness, fatigue, and mood changes. High doses may cause anxiety, extreme fear, and delusions.

Recreational Use

When it comes to recreational use, several hospital reviews and clinical trials found that magic mushrooms can cause [20, 21, 22, 23, 24, 25]:

  • Unease, accompanied by anxiety, agitation, and panic reactions
  • An altered sense of time, place, and recognition, and depersonalization
  • Rarely, high blood pressure or an increased heart rate
  • Nausea/vomiting, muscle pain, fever
  • Widening of eye pupils

No deaths or serious damage has been linked to psilocybin-containing mushrooms to date. Serious damage or disease was only linked to cases of people who consumed poisonous mushrooms under the belief they are psilocybin-containing varieties. Other times, psilocybin was combined with various other substances of abuse.

Rarely, psychedelic effects, flashbacks, delusions, and cognitive changes continue long after recreational use for unknown reasons. This is called the hallucinogen persisting perception disorder (HPPD) [26, 27].

Recreational use of psilocybin may cause anxiety, panic attacks, and depersonalization. It may cause persisting hallucinations in rare cases.

People with Schizophrenia or Psychosis

In some milder ways, psilocybin mimics schizophrenia in healthy individuals. This refers to the hallucination, changes in perception, and delusions that can be ascribed to psilocybin [28, 29].

LSD and amphetamines might trigger schizophrenia in genetically-prone people, but no studies have shown that psilocybin causes or triggers psychosis or schizophrenia in any way [30].

However, the majority of clinical trials excluded people with psychosis or schizophrenia. That means we don’t know how psilocybin could affect people with schizophrenia.

Some effects of psilocybin may resemble schizophrenia, but there isn’t enough evidence to determine the risk of long-term psychosis or similar side effects.

Limitations and Caveats

Although the research about the therapeutic potential of psilocybin is growing, psilocybin remains classified as a Schedule I drug. Until more research emerges or regulations change, psilocybin use outside of a research/medical environment is not considered safe.

Can You Buy Magic Mushrooms Online?

I know many of you are expecting a buy link somewhere in this post, but it’s still not legal to buy or sell psilocybin in most US states (or in other parts of the world).

You can buy a mushroom growing kit on Amazon, though.

This section contains sponsored links, which means that we may receive a small percentage of the profits from your purchase, while the price remains the same to you. The SelfDecode marketing and content department are purposely kept separate so that our scientists are not influenced by any pressure to write about a substance in a positive light. The proceeds from your purchase support our research and work. Thanks for your support!

Learn More About Psychedelics

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Psilocybin is a naturally occurring, illegal psychedelic produced by psilocybe mushrooms. It has a long history of use as a recreational hallucinogen, and researchers have long suspected that it may have a future of medicinal use. However, it is currently a schedule I drug with no approved uses.

People who take psilocybin report that it alters sensory perception, alters consciousness, and changes self-perception. Adverse effects include extreme fear, delusions, dizziness, unusual sensations, and an altered perception of time.

About the Author

Ana Aleksic

Ana Aleksic

MSc (Pharmacy)
Ana received her MS in Pharmacy from the University of Belgrade.
Ana has many years of experience in clinical research and health advising. She loves communicating science and empowering people to achieve their optimal health. Ana spent years working with patients who suffer from various mental health issues and chronic health problems. She is a strong advocate of integrating scientific knowledge and holistic medicine.


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