Short answer: Psilocybin is the psychedelic compound in "magic mushrooms". It is Schedule I under federal law, but Oregon and Colorado run state-regulated psilocybin services for adults, and a synthetic psilocybin treatment for depression was under rolling FDA review in 2026. Physical toxicity is low, but frightening experiences, risky behavior, and psychosis in vulnerable people are real risks.
Key takeaways
- What it is: Psilocybin is a serotonergic psychedelic (tryptamine) and a Schedule I controlled substance in the US.
- Medical use: Investigational (depression); state programs.
- Timing: effects start in 20 to 40 minutes and last 4 to 6 hours.
- Most dangerous mix: Lithium, which can cause seizures and dangerous reactions reported.
- Naloxone: it does not reverse this drug, but give it whenever opioids could be involved.
- Dependence risk: Low.
- Legal route: none. Schedule I substances cannot be prescribed.
What is psilocybin?
Psilocybin is found in more than 200 species of mushrooms. The body converts it to psilocin, which activates serotonin 5-HT2A receptors and alters perception, mood, and thinking.
Effects include changes in vision and hearing, intensified emotions, a distorted sense of time, feelings of connection or insight, and sometimes anxiety, confusion, or fear. Physical effects include nausea, yawning, dilated pupils, and raised heart rate and blood pressure.
Quick facts
| Fact | Psilocybin |
|---|---|
| Chemical | Psilocybin (converted to psilocin in the body) |
| Common names | Magic mushrooms, shrooms |
| Drug class | Serotonergic psychedelic (tryptamine) |
| US legal status | Schedule I federally; state-regulated programs in Oregon and Colorado |
| Medical status | Investigational; COMP360 new drug application under rolling FDA review (2026) |
| How it is used | Dried mushrooms eaten or brewed as tea; synthetic capsules in trials |
| Onset | 20 to 40 minutes |
| Duration | 4 to 6 hours |
| Half-life | Psilocin: about 2 to 3 hours |
How long does psilocybin last?
- Starts working: 20 to 40 minutes
- Effects last: 4 to 6 hours
- Half-life: Psilocin: about 2 to 3 hours
Psilocin is mostly cleared within a day, and standard drug tests do not detect it.
Timing varies with the dose, the form, how it is taken, liver and kidney function, age, and other drugs taken at the same time.
What are the biggest risks of psilocybin?
Psychological risks: panic, paranoia, and frightening experiences ("bad trips") can lead to dangerous behavior, accidents, or self-harm. People with a personal or family history of psychosis or bipolar disorder are at higher risk of lasting psychiatric effects.
Mistaken identity: wild mushrooms can be confused with poisonous species, some of which cause fatal liver failure.
Physical risks are low in healthy adults, but rising heart rate and blood pressure can be dangerous for people with heart disease.
What should you never mix with psilocybin?
| Combined with | What happens | Risk level |
|---|---|---|
| Lithium | Seizures and dangerous reactions reported | Avoid |
| MAOIs (and ayahuasca) | Greatly intensified, unpredictable effects | High risk |
| SSRIs and SNRIs | Usually blunted effects; serotonin syndrome possible with some combinations | Use caution |
| Cannabis | More intense, sometimes frightening experiences | Use caution |
| Stimulants (amphetamines, cocaine) | Anxiety, heart strain, overheating | Use caution |
Check any combination with the DoseUses combination checker or ask a pharmacist.
What are the signs of a psilocybin overdose, and what should you do?
Psilocybin has very low physical toxicity, and deaths from psilocybin alone are extremely rare. Large doses can cause overwhelming fear, confusion, vomiting, high blood pressure, and dangerous behavior. Seizures and severe reactions are more likely when mixed with lithium or other drugs.
If someone is having a dangerous reaction
- Call 911 for a seizure, chest pain, a very high temperature, trouble breathing, unresponsiveness, or if the person may harm themselves or others.
- Move them to a quiet, safe place away from roads, water, heights, and crowds. Stay with them and speak calmly.
- Do not leave the person alone and do not give them other drugs or alcohol to calm them down.
- If they become unresponsive, place them on their side and give naloxone in case opioids are involved.
Is psilocybin addictive?
Psilocybin is not considered physically addictive and does not cause a withdrawal syndrome. Tolerance builds within a day or two and fades after about a week. Some people use it compulsively, but this is uncommon.
See the withdrawal timelines and the full psilocybin withdrawal guide.
Is psilocybin legal?
Psilocybin is a Schedule I controlled substance under federal law, meaning it is considered to have a high potential for abuse and no currently accepted medical use. It cannot be prescribed, and possessing, making, or selling it is a federal crime.
- Possession: under federal law, a first conviction for possessing any controlled substance without a valid prescription can bring up to one year in prison and a minimum fine of $1,000. Penalties rise with prior convictions.
- Selling or sharing: distribution carries much heavier federal penalties, which increase with the amount involved and are higher still if the drug causes death or serious injury.
- State law: states set their own penalties, and most drug cases are prosecuted under state law. Penalties range from a civil fine to long prison terms depending on the state, the amount, and prior record.
Outside the United States
| Country | Status |
|---|---|
| Australia | Schedule 8 for prescribing by authorised psychiatrists for treatment-resistant depression since 2023; otherwise prohibited |
| Canada | Schedule III; access through Health Canada exemptions and the Special Access Program |
| Netherlands | Mushrooms banned since 2008; psilocybin truffles sold legally |
| United Kingdom | Class A |
| International | Schedule I of the 1971 Convention on Psychotropic Substances |
Frequently asked questions about psilocybin
Is psilocybin legal in Oregon?
Yes, within the state program: adults 21 and over can use it at licensed service centers with a facilitator. It remains illegal under federal law.
Is psilocybin FDA-approved?
Not yet. COMP360, a synthetic psilocybin for treatment-resistant depression, was under rolling FDA review in 2026.
Are magic mushrooms addictive?
Psilocybin is not physically addictive and does not cause withdrawal. Tolerance builds quickly.
Can you take psilocybin on antidepressants?
SSRIs often blunt its effects. Lithium combined with psychedelics has been linked to seizures and should be avoided.
How long does psilocybin stay in your system?
Psilocin is mostly cleared within a day, and standard drug tests do not detect it.
Sources
- Psilocybin (Magic Mushrooms), National Institute on Drug Abuse.
- Compass Pathways Form 8-K, July 7, 2026 (COMP360 phase 3 results and NDA status), US Securities and Exchange Commission.
- Psychedelic and Dissociative Drugs, National Institute on Drug Abuse.
- Controlled Substance Schedules, DEA Diversion Control Division.
- 21 U.S.C. 844, Penalties for simple possession, Legal Information Institute, Cornell Law School.
- 21 U.S.C. 841, Prohibited acts A (trafficking penalties), Legal Information Institute, Cornell Law School.
- Oregon Psilocybin Services, Oregon Health Authority.
- Executive order aims to accelerate approval of therapeutic psychedelics, Morgan Lewis, April 2026.
This guide summarizes the sourced DoseUses Psilocybin profile, written from FDA labels, DEA rules, and federal health agencies. It is educational and is not medical advice. Last updated October 5, 2026.
