Magic mushrooms vs weed: how psilocybin and cannabis compare on effects, risks and the law

People often ask how magic mushrooms compare with weed, sometimes because cannabis is legal in Canada and mushrooms are not. The two are often grouped together, but they differ in how they act on the brain, how long they last, how likely they are to lead to problem use, and how the law treats them.

This page compares them one topic at a time, using Health Canada, CAMH, Canadian law and published studies. It does not cover using the two together: that is in our guide to mixing magic mushrooms with alcohol, cannabis and other drugs. It does not say whether anyone should use either, and it gives no amounts.

How do psilocybin and cannabis act on the brain?

Through different receptor systems. The body turns psilocybin into psilocin, and psilocin’s effects depend mainly on the serotonin 2A (5-HT2A) receptor. In a 1998 study of healthy volunteers, the psychosis-like effects of psilocybin were blocked by ketanserin, a drug that blocks 5-HT2A receptors, and by the antipsychotic risperidone (Vollenweider et al., 1998). A 2019 brain-imaging study of eight volunteers found that how intense people rated the experience tracked how many 5-HT2A receptors were occupied and how much psilocin was in their blood (Madsen et al., 2019). Our page on psilocin vs psilocybin explains the chemistry.

Cannabis contains many compounds called cannabinoids. Health Canada says THC (delta-9-tetrahydrocannabinol) is responsible for the high and intoxication, and that “unlike THC, CBD does not produce a high or intoxication”. It adds that there is some evidence CBD may block or lower some of THC’s effects on the mind (Health Canada, about cannabis). A pharmacology review describes THC as the main psychotropic part of cannabis and a partial agonist (a partial activator) at cannabinoid CB1 and CB2 receptors, while CBD can act against drugs that activate those receptors in laboratory tests (Pertwee, 2008).

So the comparison is mostly psilocybin against THC. CBD is a separate question, and the risks below are mainly about THC-containing cannabis. How psilocybin compares with LSD and DMT, which share its receptor target, is covered in psilocybin, LSD and DMT compared.

How do the effects and their duration compare?

Health Canada lists the short-term mental effects of magic mushrooms as heightened emotions and senses, hallucinations, a distorted sense of reality and time, mood changes, and sometimes anxiety, panic, confusion, fear or paranoia. It says effects appear within 15 to 45 minutes and usually last four to six hours (Health Canada, magic mushrooms). For more detail, see how long do magic mushrooms last? and magic mushroom effects, short and long term.

For cannabis, Health Canada lists euphoria, a sense of well-being, relaxation and heightened senses, alongside confusion, sleepiness, impaired memory, concentration and reaction time, and anxiety, fear or panic (Health Canada, health effects of cannabis). Timing depends on how it is taken. CAMH says smoking has an almost immediate effect that typically lasts one to three hours, while edibles can take up to two hours to start and can last up to 12 hours (CAMH, cannabis). Health Canada says effects can last up to 24 hours (Health Canada, health effects of cannabis).

The kinds of experience differ too. Hallucinations and a changed sense of reality are central to the mushroom experience in Health Canada’s list. For cannabis, they appear only in its description of psychotic episodes, which are discussed below.

Is weed or shrooms more addictive?

On the evidence we found, cannabis carries the clearer risk of dependence. Health Canada estimates that 1 in 3 people who use cannabis will develop a problem with their use and that 1 in 11 (9%) will develop an addiction to it. It says this rises to about 1 in 6 (17%) for people who started as teenagers, and that the risk of addiction is 25% to 50% for people who smoke cannabis daily (Health Canada, addiction to cannabis).

A 2020 meta-analysis of 21 population studies put the figure higher, depending on the definition used: among people who had used cannabis, 22% had a cannabis use disorder. In cohort studies, the risk of cannabis dependence was 33% among young people who used weekly or daily (Leung et al., 2020). CAMH says regular users can develop cannabis use disorder, that the risk is much higher for people who start before age 18, and that stopping can cause withdrawal: irritability, anxiety, upset stomach, loss of appetite, mood swings, sweating and disturbed sleep, typically for one to two weeks (CAMH, cannabis). Evidence: established.

For magic mushrooms, Health Canada says “there is little evidence that people can become physically or psychologically dependent” on them, although tolerance can build with regular use (Health Canada, magic mushrooms). A 2018 review of psilocybin’s abuse potential found limited reinforcing effects in animals, with only “marginal, transient” self-administration, and noted that a few lifetime uses is the normal pattern among people who use mushrooms. It still concluded psilocybin has enough abuse potential to justify control (Johnson et al., 2018). Evidence: established that dependence is uncommon, not that it never happens. Our guide are magic mushrooms addictive? covers tolerance and withdrawal in more detail.

One caution about comparing them. We found no study that measured dependence on both drugs in the same people with the same method. The comparison here is across separate sources, and the much larger number of cannabis users means its problems are far better measured.

What physical risks does each carry?

Health Canada’s list of physical effects of magic mushrooms includes a faster heart rate and higher blood pressure, nausea and vomiting, muscle weakness, twitching or convulsions, sweating, high body temperature, chills and loss of urinary control (Health Canada, magic mushrooms). In a small placebo-controlled study of eight healthy volunteers, blood pressure rose moderately, and only at the highest dose tested, while heart tracings (ECG) and body temperature were not affected (Hasler et al., 2004). A 2022 review concluded that the medical risks of classic psychedelics are often minimal (Schlag et al., 2022). The bigger physical danger with mushrooms is picking the wrong one: some wild mushrooms are deadly, which is covered in poisonous mushrooms in Ontario.

For cannabis, Health Canada lists a faster heart rate, which it says can be dangerous for people with heart conditions, lower blood pressure that can cause fainting, and damage to blood vessels from smoking (Health Canada, health effects of cannabis). Cannabis hyperemesis syndrome, repeated bouts of severe vomiting linked to long-term use, has become a growing reason for emergency visits in Ontario. One study counted 12,866 such visits between 2014 and mid-2021; the monthly rate rose 13-fold over the period, and 8.8% of visits led to a hospital admission (Myran et al., 2022). Evidence: established for the listed effects; the Ontario figures come from health records, which show trends but not every cause.

Can shrooms or weed cause psychosis?

Both have been linked to psychosis, but the evidence is of different kinds. For cannabis, the link is backed by large studies. Health Canada says daily or near-daily use can increase the chance of psychosis and schizophrenia, that this is more likely in people with a personal or family history of mental illness, and that cannabis can interfere with brain development until around age 25 (Health Canada, cannabis and mental health). CAMH says cannabis can increase the risk of schizophrenia and bipolar disorder (CAMH, cannabis).

In a European case-control study of 901 people with a first episode of psychosis and 1,237 controls, daily cannabis use was linked to about three times the odds of psychotic disorder, and daily use of high-potency cannabis to nearly five times (Di Forti et al., 2019). In Ontario, a cohort study of more than 13.5 million people found that 8.9% of those with a cannabis use disorder developed schizophrenia, against 0.6% of others. The share of new schizophrenia cases associated with cannabis use disorder nearly tripled, from 3.7% before legalization to 10.3% after, and reached 18.9% among men aged 19 to 24 (Myran et al., 2025). Another Ontario study found emergency visits for cannabis-induced psychosis rose once the legal market expanded its stores and products, but not during the earlier, restricted period (Myran et al., 2023). These are associations; they cannot prove cause on their own. Evidence: established that heavy use is linked to psychosis.

For magic mushrooms, Health Canada says only that people predisposed to or living with psychiatric conditions may have a higher risk of side effects (Health Canada, magic mushrooms). A review of psilocybin’s abuse potential lists making mental illness worse in people with, or predisposed to, psychotic disorders among its potential harms (Johnson et al., 2018). A US population survey of more than 130,000 adults found no link between lifetime psychedelic use, including psilocybin, and later mental health problems such as psychosis symptoms (Krebs and Johansen, 2013).

A large Ontario study points the other way for one group. Among more than 9.2 million people, those who had an emergency visit involving hallucinogens were far more likely to be diagnosed with a schizophrenia-spectrum disorder within three years: 3.99% against 0.15% of the general population. After adjusting for other substance use and mental health conditions, the risk was still about 3.5 times higher, and about 1.5 times higher than after an emergency visit involving cannabis (Myran et al., 2025). The authors say their study could not establish cause, and that the “hallucinogen” category also included LSD, MDMA and ketamine, not just psilocybin. It describes people whose use led to an emergency visit, not everyone who uses. Evidence: preliminary for psilocybin specifically. Our article can magic mushrooms cause psychosis? goes further.

What does Canadian law say about driving after weed or shrooms?

Driving while impaired by any drug is a criminal offence, and federal regulations also set blood-drug limits. For THC, the Blood Drug Concentration Regulations set a lower limit of 2 ng per mL of blood for a summary offence and 5 ng per mL for the more serious hybrid offence. For psilocybin and psilocin, the limit is “any detectable level” (Justice Laws, Blood Drug Concentration Regulations). Ontario also says you cannot consume cannabis in a vehicle or boat that is being driven or will be driven (Ontario, cannabis laws).

Legal cannabis is not legal to drive on (Justice Canada). For roadside testing, licence suspensions and penalties in Ontario, see driving after magic mushrooms in Ontario.

Why is weed legal in Canada and shrooms are not?

Because Parliament passed a law for cannabis and has not done so for psilocybin. The Cannabis Act received royal assent on 21 June 2018 (Justice Laws, Cannabis Act), and Justice Canada describes what became legal as of 17 October 2018. It sets the federal minimum age at 18 and says provinces and territories can set a higher age but not a lower one (Justice Canada). The Act says its purpose is to protect public health and public safety, including protecting young people by restricting their access and providing for legal production to reduce illegal activity (Justice Laws, Cannabis Act).

Ontario’s rule is “19 and older to buy, use, possess and grow recreational cannabis” (Ontario, cannabis laws). Legal does not mean unrestricted. The Act prohibits adults from possessing cannabis they know is illegal cannabis (Justice Laws, Cannabis Act), and Justice Canada says giving or selling cannabis to anyone under 18, illegal sale and taking cannabis across Canada’s borders can each bring up to 14 years in jail (Justice Canada).

Psilocybin is different. In the Controlled Drugs and Substances Act consolidation current to 30 September 2026, psilocin and psilocybin are items 11 and 12 of Schedule III, while the old cannabis entry in Schedule II is marked as repealed by the Cannabis Act (Justice Laws, CDSA). Health Canada says that “the production, sale and possession of magic mushrooms are illegal in Canada” (Health Canada, magic mushrooms). For exemptions, the Special Access Program and the BC pilot, see are magic mushrooms legal in Canada?.

Magic mushrooms vs weed at a glance

What is still not known?

• Whether psilocybin causes psychosis, or whether people already at risk are more likely to use it or to end up in emergency care. The Ontario hallucinogen data could not separate psilocybin from other drugs (unresolved).
• How common problem use of magic mushrooms is in the general population, measured the same way as cannabis use disorder (unresolved).
• How much of the cannabis and psychosis link is caused by cannabis itself, and how much by other factors (largely settled for heavy, high-potency use; still debated in detail).
• How the effects of legal, commercial cannabis markets will change these figures over time; Ontario studies show some rises after the market expanded (preliminary).

If cannabis or any other substance is causing problems for you or someone close to you, a doctor, nurse or pharmacist can talk through the options. In a crisis, call or text 9-8-8, and call 911 if anyone’s safety is at risk.

Shroomverse sells mushroom products. This article is general information comparing psilocybin and cannabis. It is not medical, legal or purchasing advice, and it does not recommend any product.