Know these first
- Never combine psilocybin with lithium. In one analysis of 62 reports, 47% described seizures.
- Antidepressants (SSRIs and SNRIs) often weaken psilocybin's effects. Don't stop them on your own; talk to your prescriber.
- A personal or family history of psychosis or bipolar disorder raises the risk of serious psychiatric reactions.
- Wild mushrooms can kill. If anyone may have eaten a misidentified mushroom, call the Washington Poison Center at 1-800-222-1222 now, before symptoms.
- In Washington, people who call for help in an overdose are protected from possession charges based on that call (RCW 69.50.315). In an emergency, call 911.
On this page
Call 911 for seizures, chest pain, trouble breathing, unresponsiveness, overheating, or anyone at risk of hurting themselves or others. For a possible poisoning, including any wild mushroom, call the Washington Poison Center at 1-800-222-1222, 24 hours a day.
How risky is psilocybin?
Physically, less than most drugs people use recreationally. Psilocybin isn't considered addictive, and its toxic dose is far above the amounts people take; researchers' long-standing safety guidelines put its main risks in behavior and psychology rather than organ damage (Johnson, Richards and Griffiths, 2008). Oregon's licensed program gives a real-world picture: across 5,935 clients in 2025, facilitators reported calling emergency services 13 times (OHA). That's a screened, supervised population. Unscreened use, unknown potency and no sitter make the numbers worse.
The serious harms cluster in a few places:
- dangerous drug combinations, lithium above all;
- people with a vulnerability to psychosis or mania;
- accidents and risky behavior while affected, including driving;
- misidentified wild mushrooms, which is a poisoning risk rather than a psilocybin risk.
Medication interactions
| Medication | What's known | What to do |
|---|---|---|
| Lithium | Of 62 online reports of lithium taken with a classic psychedelic, 47% described seizures and 39% involved medical attention. No seizures were reported with lamotrigine (Nayak et al., 2021). | Don't combine. Oregon's licensed program says clients who've taken lithium in the past 30 days may be ineligible. |
| SSRIs and SNRIs (sertraline, escitalopram, fluoxetine, venlafaxine and others) | Often weaken psilocybin's effects, sometimes for weeks to months after stopping (Gukasyan et al., 2023). In one controlled study, escitalopram reduced anxiety and bad effects without cutting the positive ones (Becker et al.). | Don't stop or skip doses on your own. Talk to your prescriber. Weaker effects tempt people to take more, which raises other risks. |
| MAO inhibitors (some antidepressants; also in ayahuasca) | Lab studies disagree on how much MAO-A breaks down psilocin; inhibiting it could increase and prolong exposure. Human data are thin. | Treat as risky. Don't combine without medical advice. |
| Antipsychotics and mood stabilizers | Taken for conditions that are themselves reasons for caution with psilocybin. | Talk to your prescriber; don't adjust medication yourself. |
| Alcohol, cannabis, other drugs | Combinations make effects less predictable and can intensify anxiety. | Avoid mixing, especially the first time. |
Who should avoid psilocybin
- People with a personal or close family history of schizophrenia, psychosis or bipolar disorder. Lifetime psychedelic use has been linked to more psychotic symptoms specifically in people with a family history of those conditions (Simonsson et al., 2023), and naturalistic use to more manic symptoms in people with a personal history of bipolar I or schizophrenia (Simonsson et al., 2025). Clinical trials routinely exclude these groups.
- People with heart disease or uncontrolled high blood pressure. Psilocybin temporarily raises heart rate and blood pressure. Separately, long-term repeated use, as in microdosing, raises a theoretical heart-valve concern through the 5-HT2B receptor that hasn't been properly studied (Tagen et al.).
- People who are pregnant or breastfeeding, because there's no safety data.
- Anyone in an acute crisis. Psilocybin intensifies what's already there. It isn't a crisis intervention; if you're thinking about suicide, call or text 988.
Setting yourself up safely
Researchers talk about set (your state of mind and expectations) and setting (the place and the people). The practical version:
- Have a sober person you trust with you.
- Choose a private, familiar, safe place. Avoid water, heights, traffic and crowds.
- Don't drive until the effects have fully worn off. Driving while affected by any drug is DUI in Washington.
- Know your medications, and check the interaction table above first.
- Remember that public use isn't covered by Seattle's resolution and is prosecutable under city and state law.
Difficult experiences
Fear, confusion, paranoia and overwhelming emotion are common enough that trials plan for them. Most pass as the drug wears off. If you're with someone who's struggling:
- Move them somewhere quiet and safe, and stay with them.
- Speak calmly and simply. Remind them they've taken something, it will wear off, and they're safe.
- Offer water and a blanket. Don't give alcohol or other drugs.
- Call the Fireside Project, a free psychedelic peer support line: call or text 62-FIRESIDE (623-473-7433), 11 a.m. to 11 p.m. Pacific, every day. They also help people make sense of an experience afterward.
- Call 911 if there's a seizure, chest pain, trouble breathing, extreme agitation, overheating, unresponsiveness, or any risk of harm.
Washington's Good Samaritan law protects both the person who calls for help in a drug-related overdose and the person who needs it from possession charges based on evidence found because of the call (RCW 69.50.315). Don't let fear of a possession charge stop you from calling.
Wild mushrooms: a different and deadlier risk
Western Washington's wood chips and lawns grow psilocybin species and deadly amatoxin-containing mushrooms side by side. Galerina marginata in particular grows in the same habitat as wavy caps and can fool people who think they know what they're looking at. Amatoxin poisoning usually takes 6 to 24 hours to cause symptoms, then can destroy the liver. Early treatment matters, so:
- Call the Washington Poison Center at 1-800-222-1222 as soon as you suspect anyone ate a mushroom that wasn't positively identified, even if they feel fine.
- Keep any leftover mushroom, or take a photo, for identification.
- Don't wait for vomiting or stomach pain to start.
Our guide to wild psilocybin mushrooms in Washington covers the species and their lookalikes.
Unknown products
With no regulated supply in Washington, you rarely know exactly what you have. An Ehrlich reagent test from a harm-reduction group like DanceSafe can show whether an indole like psilocybin is present but can't tell you strength.
Common questions
Can you overdose on psilocybin mushrooms?
Psilocybin's physical toxicity is low, and deaths from psilocybin alone are very rare. A large amount can still cause an overwhelming, frightening experience, vomiting, a fast heart rate and raised blood pressure, and the real dangers come from accidents, risky behavior, drug combinations and misidentified wild mushrooms. If someone is unresponsive, having a seizure, having chest pain or is a danger to themselves or others, call 911.
Is it safe to take psilocybin with antidepressants?
SSRIs and SNRIs often blunt psilocybin's effects, and the dampening can last for weeks after stopping. The bigger danger is stopping an antidepressant suddenly to make room for psilocybin, which can cause withdrawal and relapse. Lithium is the medication to never combine. Talk to the person who prescribes your medication.
Who should not take psilocybin?
Anyone taking lithium; anyone with a personal or close family history of schizophrenia, psychosis or bipolar disorder; people with heart disease or uncontrolled high blood pressure; and people who are pregnant or breastfeeding, for whom there's no safety data. Clinical trials and Oregon's licensed program screen for these.
Will I get in trouble for calling 911 after taking mushrooms in Washington?
Washington's Good Samaritan law (RCW 69.50.315) says a person who seeks medical help in good faith for someone experiencing a drug-related overdose, and the person who overdosed, can't be charged with possession based on evidence found because of that call. It doesn't cover other crimes. When someone's health is at risk, call.
What should I do if someone is having a bad trip?
Move them somewhere quiet and safe, stay with them, speak calmly and remind them that what they're feeling is the drug and will pass. Don't give them other substances. The Fireside Project's peer support line, 62-FIRESIDE (623-473-7433), takes calls and texts from 11 a.m. to 11 p.m. Pacific. Call 911 for any physical emergency or if they're a danger to themselves or others.
Sources
- Nayak et al., "Classic psychedelic coadministration with lithium, but not lamotrigine, is associated with seizures," Pharmacopsychiatry (2021)
- Gukasyan et al., "Attenuation of psilocybin mushroom effects during and after SSRI/SNRI antidepressant use," Journal of Psychopharmacology (2023)
- Becker et al., psilocybin after escitalopram or placebo pretreatment, Clinical Pharmacology & Therapeutics (2021)
- Simonsson et al., "Psychedelic use and psychiatric risks," Psychopharmacology (2023)
- Simonsson et al., naturalistic psychedelic use and psychotic and manic symptoms, Psychological Medicine (2025)
- Johnson, Richards and Griffiths, "Human hallucinogen research: guidelines for safety," Journal of Psychopharmacology (2008)
- Tagen et al., "The risk of chronic psychedelic and MDMA microdosing for valvular heart disease," Journal of Psychopharmacology (2023)
- Oregon Health Authority, Oregon Psilocybin Services 2025 year-end data summary
- Oregon Health Authority, accessing psilocybin services (screening)
- RCW 69.50.315, medical assistance in drug-related overdose
- Washington Poison Center, "A mushroom PSA" (2025)
- Puget Sound Mycological Society, mushroom poisoning
- Fireside Project
Last checked against the sources above on Oct 20, 2026. Spotted something out of date? Tell us.