Safety & Risks

We would much rather you have a good experience than a big one. This guide brings together the most important things to know about reducing the risks of psilocybin mushrooms. It draws on published safety guidance from clinical researchers, on Health Canada's public information and on long-standing harm reduction practice.

Nothing here is medical advice, and no guide can make any drug risk-free. If you have health questions, please talk to a doctor, nurse or pharmacist. They are there to help you, not to judge you.

Understanding the risks honestly

Compared with many other substances, psilocybin has low physical toxicity, and it is not considered to cause physical dependence. Michael Pollan, summarizing the research, put it simply on NPR's Fresh Air: "Physiologically, they're - you know, they're relatively nontoxic" (NPR). But low toxicity is not the same as low risk.

The main risks of psilocybin are psychological and behavioural. Health Canada lists anxiety, panic, fear and paranoia among the possible short-term effects, along with nausea, vomiting and increased heart rate and blood pressure. It also warns that a difficult experience can impair judgement in ways that lead to injury. In a small number of people, particularly those with a personal or family history of psychosis, psychedelics may trigger longer-lasting mental health problems. Clinical trials, with all their safeguards, still record side effects. In the 2022 trial of single-dose psilocybin for treatment-resistant depression published in the New England Journal of Medicine, which involved 233 participants, adverse events such as headache, nausea and dizziness were common, and suicidal ideation or self-injury was reported in every dose group. Most serious harms are linked to unsafe settings, high doses, mixing substances or underlying conditions, which is why the rest of this guide focuses on those.

Who should not use mushrooms

Clinical research teams screen participants carefully before giving psilocybin. Their exclusion criteria are a sensible guide for everyone. Do not use psilocybin mushrooms if any of the following apply to you:

You are under 19.
You are pregnant, trying to become pregnant or breastfeeding.
You have a personal or close family history of psychosis, schizophrenia or bipolar disorder.
You have heart disease, uncontrolled high blood pressure or a history of stroke, unless a doctor has advised you.
You have a seizure disorder.
You take lithium, or medications that may interact (see below), without medical advice.
You are in crisis, feel unsafe or are going through a period of severe stress.

If you are unsure whether something on this list applies to you, treat that as a reason to wait and ask a health professional first.

Medication interactions

Psilocin acts on the serotonin system, so any medication that also works on serotonin deserves attention. Bring your full medication list, including supplements, to a pharmacist or doctor and ask directly.

SSRIs and SNRIs: common antidepressants such as sertraline, escitalopram, fluoxetine and venlafaxine. Research from Johns Hopkins, drawing on reports from people who had used psilocybin mushrooms, found that these medications often reduced or blunted the experience. That can lead people to take more, which is risky. Never stop an antidepressant to make room for mushrooms; stopping suddenly can cause withdrawal symptoms and a return of the condition it treats.
Lithium: in an analysis of online experience reports published in 2021, researchers found that 47 percent of 62 reports describing lithium combined with a classic psychedelic involved seizures. This is the clearest interaction warning in the field. Do not combine lithium with psilocybin.
MAOIs: monoamine oxidase inhibitors, including some older antidepressants and certain botanical brews, can intensify and prolong psilocybin's effects in ways that are hard to predict. Avoid the combination.
Antipsychotics and mood stabilizers: these can change or block effects, and the conditions they treat are themselves reasons for caution.
Tramadol, stimulants and other serotonergic drugs: these add to the strain on the serotonin system and the cardiovascular system. Ask a pharmacist.

Start low, go slow

Psilocybin content in dried mushrooms varies naturally, often by a factor of two or more between batches of the same strain. A dose that felt gentle last time may not feel gentle from a new bag. That is why experienced people treat every new strain, product or batch as unknown.

Begin with a small amount. Wait at least two hours before considering more, and in most cases do not take more at all: plan to try a slightly different amount on another day instead. Edibles and capsules can take longer to begin, especially after a meal, which is the classic setup for accidental over-dosing. Read every label, and never assume one brand's portion matches another's. Our magic mushrooms guide describes how dose ranges are usually discussed.

Set and setting

"Set" is your mindset. "Setting" is your environment. Clinical researchers treat both as part of the intervention, not as background. A widely cited 2008 paper by Matthew Johnson, William Richards and Roland Griffiths, setting out safety guidelines for hallucinogen research, emphasizes careful screening, thorough preparation, a comfortable and safe physical space, and the continuous presence of trained monitors.

Outside a clinic, you can borrow the spirit of those guidelines:

Choose a day when you feel rested and emotionally steady, with no obligations that day or the next morning.
Choose a private, familiar place where you will not be interrupted, with soft lighting, comfortable seating, blankets, water and simple food.
Prepare a playlist in advance, ideally calm and mostly instrumental.
Put your phone on Do Not Disturb, and keep it charged for emergencies.
Remove anything that could cause harm, and avoid balconies, water, traffic and heights.

Have a sober sitter

For anything beyond a very low dose, have a trusted, sober friend with you. A good sitter stays calm, keeps the space safe, helps with water and music, and offers reassurance without trying to steer the experience. They should know what you have taken, how much and when, and they should know when to call for help. Agree beforehand on how you would like to be supported, including whether you are comfortable being touched, for example a hand on the shoulder.

Do not mix

Avoid alcohol, cannabis and other drugs before, during and after. Combining substances makes effects harder to predict, raises the risk of nausea, confusion and panic, and puts more strain on the heart. Cannabis in particular is often reported to make psilocybin experiences much more intense. Caffeine can add to anxiety, so keep it modest.

Never drive

Psilocybin impairs perception, coordination and judgement. Do not drive, cycle, swim or operate machinery for the rest of the day, and wait until you feel completely normal the next day before getting behind the wheel. Driving while impaired by any drug is a criminal offence in Canada.

If things get hard

Difficult moments are common, even in good conditions, and they usually pass. These steps help:

Remind yourself of the simple facts: you took mushrooms, this is the mushrooms, and it will pass.
Breathe slowly, for example in for four counts and out for six.
Change one thing: the music, the lighting, the room, or step into fresh air if it is safe.
Hold something comforting, such as a blanket or a warm drink.
Let your sitter know how you feel. Simple, reassuring words help more than long conversations.
Try not to fight the experience. Many people find that letting a difficult feeling move through them, rather than resisting it, helps it pass.

Clinical guides prepare volunteers for these moments in advance. Michael Pollan, describing his own preparation, said the guides "give you a set of flight instructions, as they call them, which is what to do if you get really scared" (NPR). Talking through your own flight instructions with your sitter before you begin is one of the most useful things you can do.

Emergencies

Call 911 immediately if anyone has chest pain, difficulty breathing, a seizure, loses consciousness, is injured, is at risk of harming themselves or others, or cannot be calmed. Be honest with paramedics about what was taken, how much and when. It helps them treat the person quickly and safely. Canada's Good Samaritan Drug Overdose Act provides some protection from simple possession charges for people who call 911 during an overdose emergency.

If you or someone you know is thinking about suicide, call or text 9-8-8, Canada's Suicide Crisis Helpline, available at any time.

After the experience

Plan a gentle next day. Eat well, drink water, rest and give yourself some quiet time. Many people find it useful to write down what they remember while it is still fresh, and to talk it through with someone they trust. This process, often called integration, is treated by researchers and therapists as an important part of the experience. Avoid making major decisions immediately afterwards; give insights a few weeks to settle.

Some people experience lingering anxiety, low mood or unsettling thoughts after a psychedelic experience. Rarely, people report persistent visual changes. If anything like this lasts more than a few days, or worries you, please speak to a health professional. There is no shame in asking for support.

Tolerance and frequency

Tolerance to psilocybin builds quickly. Taking it again within a few days usually produces a noticeably weaker effect, which tempts some people to take more. Spacing experiences well apart is safer and, many people find, more meaningful. Microdosing routines should include regular days off and longer breaks; see our microdosing guide.

Look-alikes and foraging

Some poisonous mushrooms that grow wild in Canada can look similar to psilocybin species, and a few of them can cause organ failure or death. Never eat a wild mushroom unless it has been identified with certainty by an expert. When in doubt, leave it in the ground.

Store it safely

Keep all mushroom products locked away from children and pets, in clearly labelled original packaging. Chocolate and gummies look exactly like ordinary treats, so take extra care. If a child or pet may have eaten any, call 911 or your regional poison centre straight away. Store dried mushrooms in an airtight container somewhere cool, dark and dry.

Canadian law

Psilocybin and psilocin are controlled substances under the Controlled Drugs and Substances Act. Health Canada states that possession, sale and production are illegal unless authorized. Legal access is limited to authorized clinical trials, individual section 56 exemptions and Special Access Program requests made by health care practitioners for patients with serious conditions. You are responsible for knowing and following the laws where you live.

Questions?

Our FAQ answers many common questions about products, shipping and safe use, and you are always welcome to contact us. For anything medical, please speak with a health professional.

Sources

This guide is general information, not medical or legal advice.

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