Psilocybin Risks: Who Should Not Take It
Plain-language summary
Psilocybin is low in toxicity, but it is not safe for everyone. The biggest risks are mental, not physical. The highest risk is for people with a personal or family history of psychosis or bipolar disorder. People with serious heart problems, pregnant people, and minors should also avoid it. Bad outcomes are more likely when the mood is poor. They are also more likely with the wrong mushroom, or when someone tries to drive.
Where the real risks are
Psilocybin is the main active part of "magic mushrooms." You can read more on the basics page. Next to many other drugs, psilocybin does very little direct harm to organs.[1] It does not cause physical dependence. Tolerance builds so fast that daily use stops working — see our tolerance page.
So where is the danger? Research points to three main areas.[2] First, harm to the mind: panic, confusion, and unsafe acts during the experience. Second, harm to mental health: setting off or worsening conditions like psychosis. Third, harm from the setting: accidents, poisonous look-alike mushrooms, and mixing with other drugs. Drug mixes have their own page — see drug interactions.
Psychological risks
Psilocybin changes how you see, feel, and think for four to six hours. During that time, a person can feel strong fear, paranoia, or confusion. These are often called "bad trips." Researchers call them challenging experiences.
One large survey asked people who had a hard psilocybin experience about it. Most said the event was hard but meaningful. Still, some put themselves or others at risk of physical harm during it.[3] Higher doses made severe trips more likely.[3] A few people in that survey had lasting emotional problems afterward.[3]
The risk of panic drops a lot with good prep, a safe setting, and a sober helper.[2] Our pages on set and setting and trip sitting explain how this works. If a hard experience is already happening, see difficult experiences.
Psychosis and schizophrenia family history
This is the clearest "do not take it" group in the research. Psychosis means losing touch with reality. It can include hearing voices or holding fixed false beliefs. Schizophrenia is a long-term illness that involves psychosis.
Clinical trial safety rules exclude people with schizophrenia or other psychotic disorders. They also exclude people with a close relative — a parent, sibling, or grandparent — who has had one.[2] The worry is that psilocybin could trigger a first psychotic episode in someone who is already at risk. Once it starts, psychosis may not fully go away.
Lasting psychotic reactions after psilocybin appear to be rare in screened research volunteers.[4] But these volunteers are checked for exactly this risk. People who use psilocybin outside research are not. If you or a close blood relative has had psychosis, mania, or schizophrenia, the published safety guidance is simple: avoid psilocybin.[2]
Bipolar disorder
Bipolar disorder involves swings between very low moods and very high, driven moods called mania. Clinical safety rules also exclude people with bipolar I or II. They often exclude those with a close family history of it.[2]
The worry is twofold. Psilocybin may trigger a manic episode in a person with bipolar disorder. Also, many people with bipolar disorder take lithium. Lithium has its own serious risk when mixed with psychedelics — see drug interactions for details.
Heart conditions
Psilocybin raises heart rate and blood pressure for several hours.[1][2] For a healthy person, this rise is usually small. For someone with heart disease, it can be dangerous.
Published safety rules advise against use by people with uncontrolled high blood pressure or serious heart problems.[2] That includes a history of heart attack, heart failure, serious rhythm problems, or stroke. Stress and fear during the trip can push heart rate and blood pressure even higher. Anyone with a heart problem who is thinking about psilocybin should talk to a doctor first.
Pregnancy, breastfeeding, and minors
There is no good safety data on psilocybin in pregnancy or breastfeeding. Harm cannot be ruled out. So the standard harm-reduction view is to avoid it fully during pregnancy and while nursing.
Minors face a different problem. The brain keeps growing into the mid-20s. No research shows psilocybin is safe for growing brains, and clinical trials do not enroll minors for this reason. Teens are also less able to handle strong fear or confusion during the trip. This page, like the whole site, is education only — see our about page.
Mental state on the day
Even for people with no excluded condition, timing matters. Psilocybin tends to boost the mood you bring to it. Research on hard experiences supports this pattern.[3]
Higher-risk mental states include:
- A recent crisis, such as a breakup, job loss, or death of someone close.
- Active suicidal thoughts or severe depression.
- High anxiety, dread, or feeling pressured to take it.
- Severe sleep loss.
- Recent heavy use of alcohol or other drugs.
People who choose to use despite the risks often wait for a stable time, prepare well, and have a sober sitter present. See set and setting for what the research says about getting ready.
Physical toxicity: what research shows
Toxicity means how much a drug damages the body. Psilocybin scores low here. Reviews of the drug describe psilocybin as well tolerated by the body. There is a wide gap between an active dose and a harmful one.[1] One study compared common mind-altering drugs. It rated psilocybin mushrooms among the least deadly. The gap between a normal dose and a lethal dose is very large.[5]
Common physical effects are unpleasant but short: nausea, vomiting, higher heart rate, wide pupils, and poor balance.[1] Deaths from psilocybin poisoning alone are very rare in the medical record. Most psilocybin emergencies involve panic, injuries, other drugs, or the wrong mushroom.
Misidentified mushrooms: a hidden danger
Some of the most serious "magic mushroom" poisonings do not involve psilocybin at all. Wild mushrooms are hard to tell apart. Several deadly kinds look like psilocybin mushrooms, including some Galerina species that grow in the same places. These hold amatoxins — the same poisons found in death cap mushrooms — which destroy the liver.
Early signs of amatoxin poisoning can fade for a day before liver failure begins. Anyone who ate a wild mushroom and then gets severe stomach pain, vomiting, or diarrhea needs medical care right away. Call Poison Control. Do not wait to see if it passes. See our emergencies page for what to do and what to tell responders.
Driving and operating machines
Psilocybin harms your sight, judgment, reaction time, and balance for hours. Distances look wrong. Attention drifts. Driving, cycling in traffic, swimming, climbing, or using power tools during this window can be deadly.
Effects usually last four to six hours, but the impairment can last after the peak feels over. A sober trip sitter can block impulsive plans to go somewhere. The safest plan is simple: no travel until the next day.
Risk summary table
| Group or situation. | Main concern. | Published guidance. |
|---|---|---|
| Personal or family history of psychosis or schizophrenia. | Triggering a lasting psychotic episode. | Avoid; excluded from clinical trials.[2] |
| Bipolar disorder (I or II). | Triggering mania; lithium interaction. | Avoid; excluded from clinical trials.[2] |
| Serious heart disease or uncontrolled high blood pressure. | Raised heart rate and blood pressure for hours. | Avoid without medical advice.[2] |
| Pregnancy or breastfeeding. | No safety data; harm cannot be ruled out. | Avoid. |
| Minors (under 18). | Developing brain; no safety research. | Avoid. |
| Crisis, severe depression, or suicidal thoughts. | Amplified distress; unsafe behavior. | High risk; postpone or avoid.[3] |
| Taking interacting medicines (lithium, tramadol, MAOIs). | Seizures or dangerous potentiation. | See drug interactions. |
| Wild-picked mushrooms of unknown identity. | Amatoxin poisoning and liver failure. | Medical emergency if symptoms appear. |
| Driving or operating machines. | Impaired judgment and reaction time. | Do not drive; wait until the next day. |
For common misunderstandings about these risks, see our myths page. Unfamiliar terms are defined in the glossary.
Need help right now?
- Medical emergency (US): call 911.
- Poison Control (US): 1-800-222-1222 — free, confidential, 24/7.
- Fireside Project (psychedelic peer support line, US): call or text 62-FIRESIDE (623-473-7433).
- 988 Suicide & Crisis Lifeline (US): call or text 988.
References
- Nichols DE. Psychedelics. Pharmacological Reviews. 2016;68(2):264-355.
- Johnson MW, Richards WA, Griffiths RR. Human hallucinogen research: guidelines for safety. Journal of Psychopharmacology. 2008;22(6):603-620.
- Carbonaro TM, Bradstreet MP, Barrett FS, MacLean KA, Jesse R, Johnson MW, Griffiths RR. Survey study of challenging experiences after ingesting psilocybin mushrooms: acute and enduring positive and negative consequences. Journal of Psychopharmacology. 2016;30(12):1268-1278.
- Studerus E, Kometer M, Hasler F, Vollenweider FX. Acute, subacute and long-term subjective effects of psilocybin in healthy humans: a pooled analysis of experimental studies. Journal of Psychopharmacology. 2011;25(11):1434-1452.
- Gable RS. Comparison of acute lethal toxicity of commonly abused psychoactive substances. Addiction. 2004;99(6):686-696.