What do magic mushrooms do? Short-term and long-term effects, from the research

People ask what magic mushrooms do in several ways: what it feels like, what happens in the body, what happens in the brain, and whether anything lasts. This guide answers each from the research we could open, says how strong the evidence is, and points to our longer pages where a topic has one. It describes what studies measured. It is not a guide to using mushrooms, and it gives no amounts.

The main active compounds in magic mushrooms are psilocybin and psilocin, and Health Canada says the effects are similar to LSD, appear within 15 to 45 minutes and usually last four to six hours (Health Canada). It also says the strength of mushrooms varies greatly, so effects depend on the dose and type of mushroom, and vary from person to person. For timing in more detail, see how long do magic mushrooms last?

How do researchers measure magic mushroom effects?

Most of what is known about the acute effects comes from laboratory studies in which healthy volunteers were screened, prepared, given a measured amount of psilocybin and watched over for the whole session. Researchers then ask them to fill in standard questionnaires. Common ones include the Altered States of Consciousness Rating Scale, used in Swiss studies (Hasler et al., 2004), measures of mystical experience used at Johns Hopkins (Griffiths et al., 2006) and the Ego-Dissolution Inventory, an eight-item scale for a weakened sense of self (Nour et al., 2016).

That design matters for reading everything below. A 2008 set of safety guidelines lists the precautions these studies use: excluding people with a personal or family history of psychotic or other severe psychiatric disorders, careful preparation, a safe room and at least two monitors present (Johnson et al., 2008). A 2022 review notes that most reported adverse effects were not observed in a regulated or medical context (Schlag et al., 2022). Results from such studies describe screened people in supervised rooms, and they do not tell you what happens to someone who eats mushrooms of unknown type and strength. Evidence: established for this limitation.

What are the short-term effects of shrooms on the mind?

Health Canada’s list is the plainest summary. It says magic mushrooms may heighten emotions and senses, and that people may feel happy and creative, laugh a lot or feel a sense of mental and emotional clarity. It also lists hallucinations, a distorted sense of reality, mixed-up senses (such as believing you can see music or hear colours) and an altered sense of time. On the negative side it lists changes in mood, light-headedness, anxiety and panic attacks, confusion and disorientation, and fear or paranoia (Health Canada). Evidence: established.

A pooled analysis of eight placebo-controlled Swiss studies, covering 110 healthy volunteers tested between 1999 and 2008, found that psilocybin produced profound changes in mood, perception, thought and self-experience, and that the changes grew with the dose. Most volunteers described the experience as pleasurable, enriching and non-threatening (Studerus et al., 2011). In a smaller dose-comparison study, the higher doses halved performance on an attention test, and mood ratings showed more “general inactivation”, “emotional excitability” and “dreaminess” (Hasler et al., 2004). Evidence: established for screened volunteers in laboratory settings.

What are magic mushroom visuals like?

“Visuals” is the everyday word for the perceptual changes. Health Canada describes seeing and hearing things that are not there and senses that mix together (Health Canada). In the Johns Hopkins study, psilocybin produced a range of acute perceptual changes alongside shifting moods, including anxiety (Griffiths et al., 2006), and the Swiss pooled analysis lists perception among the domains that changed most (Studerus et al., 2011). The research measures how strong these changes are on rating scales rather than cataloguing what people see, so we do not describe particular images or patterns here. Evidence: established that perceptual changes are a core effect; limited on their exact content.

Why does time feel different, and what is “ego dissolution”?

Time is one of the few effects tested with objective tasks. In a 2007 placebo-controlled study of twelve volunteers, psilocybin impaired people’s ability to reproduce intervals longer than about two and a half seconds and to tap in time with slow beats, and it slowed their preferred tapping rate. The same volunteers reported more depersonalization and derealization, including a disturbed sense of time (Wittmann et al., 2007). Evidence: preliminary (one small study).

A changed sense of self is described so often that researchers built a scale for it. The authors of the Ego-Dissolution Inventory call a compromised sense of “self” a key feature of the psychedelic experience. In their online survey of 691 people, describing 1,828 drug experiences, ego-dissolution scores were tied specifically to experiences with psychedelics and not to those with cocaine or alcohol (Nour et al., 2016). Evidence: preliminary (a self-selected online sample, and psychedelics in general rather than psilocybin alone).

What are “mystical-type” experiences?

Some people describe a sense of unity, meaning or the sacred. A double-blind Johns Hopkins study gave psilocybin and, on another day, an active comparison drug to 36 adults who had never used hallucinogens and who took part regularly in religious or spiritual activities. Psilocybin raised scores on questionnaires measuring mystical experience, and two months later volunteers rated the experience as having substantial personal meaning and spiritual significance (Griffiths et al., 2006). At a 14-month follow-up, 58% met the study’s criteria for a “complete” mystical experience, and 67% rated it among the five most spiritually significant experiences of their lives (Griffiths et al., 2008).

Those numbers describe a small, unusual group chosen for their interest in spirituality and studied under supportive conditions. They do not predict what any one person will feel, and the same study reported anxiety during sessions. Evidence: preliminary.

What physical effects do magic mushrooms have?

Health Canada lists numbness, particularly in the face; increased heart rate and blood pressure; dry mouth, sometimes leading to nausea and vomiting; muscle weakness and twitching, or convulsions; exaggerated reflexes; sweating and high body temperature, often followed by chills and shivering; and loss of urinary control (Health Canada). The 2008 safety guidelines name dizziness, weakness, tremors, nausea, drowsiness, tingling, blurred vision, dilated pupils and increased tendon reflexes, and say hallucinogens can moderately increase pulse and blood pressure (Johnson et al., 2008). Evidence: established.

Measured in the laboratory, those changes were modest in healthy volunteers. In the Swiss dose study, average blood pressure rose moderately, and only at one time point after the highest dose; heart tracings and body temperature were not affected at any dose, while some stress-related hormones rose during peak effects (Hasler et al., 2004). The 2022 review describes the heart-rate, blood-pressure, pupil and temperature effects of psychedelics as short-lived and not clinically significant (Schlag et al., 2022). Health Canada still warns that for people with heart disease, raised blood pressure and heart rate could be harmful (Health Canada). Evidence: established for healthy volunteers; the risk for people with heart conditions is flagged, not measured.

Clinical trials in patients give a sense of how common side effects are. In a 2022 phase 2 trial in 233 adults with treatment-resistant depression, adverse events occurred in 77% of participants across all groups and included headache, nausea and dizziness (Goodwin et al., 2022). Suicidal ideation or behaviour or self-injury occurred in every group, including the comparison group, which is a reminder that trial participants were already unwell and that the trial alone cannot say how much the drug contributed. Evidence: established that headache and nausea are commonly reported in trials.

On toxicity, the 2008 guidelines say hallucinogens generally have relatively low physiological toxicity and have not been shown to cause organ damage or neuropsychological deficits, and that the main safety concerns are psychological (Johnson et al., 2008). That does not cover poisonous mushrooms mistaken for magic mushrooms, which Health Canada warns is possible because many species look alike (Health Canada). We cover both in are magic mushrooms safe? and can you overdose on magic mushrooms?

What do magic mushrooms do to your brain?

The body converts psilocybin into psilocin, which researchers describe as the active compound (Madsen et al., 2019); our page on psilocin vs psilocybin explains the chemistry. Psilocin acts on serotonin receptors, and one type, the serotonin 2A (5-HT2A) receptor, appears to be the key. In a 1998 study, the effects of psilocybin in healthy volunteers were blocked, in a dose-dependent way, by ketanserin, a drug that blocks 5-HT2A receptors (Vollenweider et al., 1998). A 2019 brain-imaging (PET) study of eight volunteers found that how strongly people rated their experience tracked how many 5-HT2A receptors psilocin occupied and how much psilocin was in their blood (Madsen et al., 2019). Evidence: established that 5-HT2A activation is central; the details of what follows are still being studied.

Brain-scan studies describe what changes across networks. A 2012 fMRI study, which gave psilocybin intravenously to 30 volunteers, found only decreases in blood flow and signal, strongest in hub regions such as the thalamus and parts of the cingulate cortex, and the size of the decrease in one frontal region predicted how intense the experience felt (Carhart-Harris et al., 2012). A 2024 study that scanned a small group of adults about 18 times each found that psilocybin massively disrupted the usual coordination between brain areas, more than threefold the change seen with a stimulant comparison drug, with the largest effects in the default mode network, which is thought to help create our sense of space, time and self (Siegel et al., 2024).

Beyond the session itself, the 2024 study also found a drop in connectivity between the front of the hippocampus and the default mode network that lasted for weeks. The authors suggest it may relate to plasticity and to therapeutic effects, which is a hypothesis, not a finding (Siegel et al., 2024). Evidence: preliminary. These are small samples, and a changed scan is not the same as a better or worse brain. For what “rewiring” can and cannot mean, see does psilocybin rewire the brain?, and for the compound itself, what is psilocybin?

What are the side effects of magic mushrooms, and what is a bad trip?

The 2008 guidelines call overwhelming distress during the drug’s action, the “bad trip”, the most likely risk, and say it could lead to dangerous behaviour such as leaving the place where a person is being looked after (Johnson et al., 2008). Health Canada says a bad trip may occur particularly at high doses, may include paranoia, loss of boundaries and a distorted sense of self, and that impaired judgment during one may lead to risk-taking, traumatic injuries or even death (Health Canada). Evidence: established.

In the Swiss pooled analysis, acute adverse reactions, marked by strong dysphoria or anxiety and panic, occurred only in the two highest dose conditions and in a relatively small share of volunteers; all were managed with interpersonal support, without medication (Studerus et al., 2011). Evidence: established for supervised laboratory settings.

Outside the laboratory, the picture comes from surveys. In a 2016 online survey, 1,993 people described their single most difficult experience with psilocybin mushrooms. Thirty-nine per cent ranked it among the five most challenging experiences of their lives, 11% said they put themselves or others at risk of physical harm, 2.6% said they behaved in a physically aggressive or violent way and 2.7% received medical help. Risk was more likely with a larger estimated dose, a longer and harder experience, and no physical comfort or social support (Carbonaro et al., 2016). Respondents were chosen for having had a bad experience, so these are not rates for all users. Evidence: preliminary.

A broader survey gives a sense of scale. Of 9,233 people in the 2017 Global Drug Survey who had used magic mushrooms in the past year, 19 (0.2%) had sought emergency medical treatment. Anxiety or panic and paranoia or suspiciousness were the most common symptoms, young age was the only predictor, poor mindset, poor setting and mixing substances were the most reported reasons, and all but one returned to normal within 24 hours (Kopra et al., 2022). Health Canada adds that combining mushrooms with cannabis, amphetamines, alcohol and similar substances elevates the risk of serious side effects (Health Canada). Evidence: preliminary for the rates; established that mixing raises risk. If you are with someone who is struggling, see how to help someone having a bad trip. Medication interactions have their own page: magic mushrooms and antidepressants.

What are the long-term effects of magic mushrooms?

Start with the gap. Health Canada says that currently no studies have evaluated the long-term effects of repetitive use of magic mushrooms (Health Canada). What exists is follow-up of research volunteers after one or a few sessions, surveys, and population data. Evidence: established that this gap exists.

In the Swiss pooled analysis, follow-up questionnaires found no later drug abuse, persisting perception disorders, prolonged psychosis or other long-term impairment of functioning in any of the 110 volunteers (Studerus et al., 2011). In the Johns Hopkins study, 64% said at 14 months that the experience had increased their well-being or life satisfaction, but on measures of personality, mood, quality of life and spirituality, only the mystical-experience scale differed from screening (Griffiths et al., 2008). Self-rated meaning is not the same as measured change. Evidence: preliminary (small, screened groups).

A 2013 analysis of 130,152 randomly selected US adults from a national survey found no significant link between lifetime use of psilocybin or other psychedelics and higher rates of the mental health problems it screened for, after controlling for other drug use and other factors (Krebs and Johansen, 2013). A survey snapshot like this cannot show cause and effect, and it cannot rule out harm to a small group. Evidence: preliminary.

Can visual effects last after a trip?

Rarely. Health Canada says flashbacks, reliving a previous experience, may be brought on by frequent or overly intense psychedelic experiences (Health Canada). When perceptual changes persist and are distressing, the condition is called hallucinogen persisting perception disorder (HPPD). The 2008 guidelines call it relatively rare (Johnson et al., 2008). The 2022 review notes that the DSM-5 figure of 4.2% of hallucinogen users comes from a single online questionnaire, while other studies report much lower rates, some as low as 1 in 50,000 (Schlag et al., 2022). Evidence: unresolved on how often it happens. Our HPPD explainer goes further.

Can magic mushrooms cause psychosis or lasting distress?

Health Canada says people predisposed to or living with psychiatric conditions may face an elevated risk of side effects, and that the association is still being evaluated (Health Canada). A 2025 meta-analysis that pooled LSD, psilocybin, mescaline, DMT and MDMA found psychedelic-induced psychosis in 0.002% of people in population studies, 0.2% in uncontrolled trials and 0.6% in randomised trials, and called most of the studies low quality (Sabé et al., 2025). In the 2016 survey of difficult experiences, 7.6% of those whose experience was more than a year earlier had sought treatment for lasting psychological symptoms, and three cases appeared linked to the onset of lasting psychotic symptoms (Carbonaro et al., 2016). Evidence: preliminary. Our page can magic mushrooms cause psychosis? covers the debate.

Are magic mushrooms addictive?

Health Canada says there is little evidence that people become physically or psychologically dependent on magic mushrooms, but that tolerance can build over several days of continued use (Health Canada). The 2022 review says tolerance develops quickly and that there is no known withdrawal syndrome, which points to a low risk of dependence (Schlag et al., 2022). Evidence: established. Low dependence risk does not make the other risks smaller.

Magic mushroom effects at a glance

What is still not known about magic mushroom effects?

• What repeated use does over months or years. Health Canada says no studies have evaluated it.
• How laboratory findings carry over to mushrooms, whose strength varies and whose species may be uncertain, taken without screening or supervision.
• Whether the lasting brain-network changes seen in small imaging studies matter for everyday life, for better or worse.
• How often rare harms such as HPPD and psychosis occur with psilocybin alone, and whether psilocybin causes them or brings forward something already present.
• How effects differ for people with heart conditions, during pregnancy, or with medications, since most studies exclude these groups.

If you have a health condition, take medication, or are worried about effects that have not gone away, the sources agree on one step: talk to a doctor or another health professional. For the full safety picture, read are magic mushrooms safe?, and for background, what are magic mushrooms?

Shroomverse sells mushroom products. This article is general information about what official sources and research say about the effects of magic mushrooms. It is not medical, legal or purchasing advice, and it does not encourage anyone to use drugs.