Shrooms

Psilocybin mushrooms ("magic mushrooms" or "shrooms") are fungi containing the psychoactive compounds psilocybin and psilocin. They produce profound alterations in perception, thought, and emotion, often described as mystical or spiritual experiences. Unlike many other recreational substances, psilocybin has remarkably low physical toxicity—but the psychological risks are real and depend heavily on who you are, how much you take, and where and how you take it.

This page helps you understand the evidence-based risks of psilocybin use. Your choices below will adjust the risk estimates to your situation.

Your Choices

What is your mindset and preparation?

What setting will you be in?

What dose are you taking?

Do you have any mental health history?

Are you taking any medications?

Your Estimated Risks

Select risk factors above...

Data, Models and References

Baseline Factors

Mindset and Preparation

Shrooms:MindsetFactor
Mindset_Description	Mindset_Multiplier
Well-prepared (clear intention, researched, calm, rested)	0.6
Moderate preparation (some research, generally positive mood)	0.8
Minimal preparation (spontaneous use, neutral mood)	1
Poor mindset (anxious, stressed, or in emotional turmoil)	1.5

"Set" refers to your mindset going into the experience—your expectations, intentions, emotional state, and preparation. A positive, prepared mindset significantly reduces the risk of challenging experiences. Being anxious, stressed, or using impulsively increases risk.

Setting

Shrooms:SettingFactor
Setting_Description	Setting_Multiplier	Setting_Safety
Clinical/therapeutic (trained facilitator, medical support)	0.5	High
Safe home environment (trusted sitter, comfortable, private)	0.7	High
Familiar social setting (trusted friends, calm environment)	1	Moderate
Unfamiliar or public setting (party, festival, strangers)	1.8	Low
Chaotic or unsafe environment (crowds, unpredictable)	2.5	Low

"Setting" refers to your physical and social environment. Clinical settings with trained facilitators have the lowest risk. Having a sober "trip sitter" and being in a comfortable, familiar place significantly reduces risk. Public, crowded, or unfamiliar environments increase the likelihood of challenging experiences.

Dose

Shrooms:DoseFactor
Dose_Description	Dose_Challenging_Baseline	Dose_mg	Dose_Dried_Grams
Microdose (sub-perceptual, 0.1-0.3g dried)	0.01	1	0.2
Low (light effects, 0.5-1.5g dried)	0.05	8	1
Moderate (full experience, 1.5-3g dried)	0.15	18	2.5
High (intense experience, 3-5g dried)	0.30	28	4
Very high (ego dissolution, 5g+ dried)	0.40	35	5.5

Dose is one of the strongest predictors of challenging experiences. In clinical trials with high doses (0.43 mg/kg, ~30mg), approximately 30% of participants experienced significant anxiety or fear. At moderate doses (0.315 mg/kg, ~20mg), only 7% reported marked anxiety. Higher doses increase both the depth of experience and the risk of difficulty.

Mental Health History

Shrooms:MentalHealthFactor
MentalHealth_Description	MentalHealth_Multiplier	MentalHealth_Contraindicated
No significant mental health history	1	No
Anxiety or depression (stable, not severe)	1.2	No
Family history of psychosis or bipolar disorder	2	Caution
Personal history of psychosis, schizophrenia, or bipolar	5	Yes
Currently in psychological crisis	3	Yes

Personal or family history of psychotic disorders (schizophrenia, bipolar with psychotic features) significantly increases risk. Most clinical trials exclude individuals with these conditions. If you have such a history, psilocybin use carries meaningful risk of triggering or worsening symptoms.

Medications

Shrooms:MedicationFactor
Medication_Description	Medication_Risk	Medication_Warning
No concerning medications	None
SSRIs or SNRIs (antidepressants)	Reduced_Effects	About half of people on these medications report weaker effects. Do not stop your medication suddenly to try to get stronger effects.
Lithium	Dangerous	Seizures have happened to many people who took psychedelics while on lithium. Do not use psilocybin while taking lithium.
Tricyclic antidepressants	Caution	May intensify effects unpredictably. Not recommended without medical guidance.
MAOIs	Caution	Can cause dangerous reactions. Requires careful timing and medical supervision.

Drug interactions with psilocybin are generally less severe than with some other substances, but lithium is a critical exception. A study of online reports found that nearly half of people who reported combining lithium with psychedelics experienced seizures. SSRIs reduce psilocybin's effects in about half of users (47% for SSRIs, 55% for SNRIs in a Johns Hopkins survey) but are not acutely dangerous.

Risk Models

RiskModel: Shrooms:ChallengingExperienceRisk
Content: 
===Risk of Challenging Experience===
Based on your selections, your estimated risk of a '''significantly challenging experience''' (marked anxiety, fear, or paranoia) is approximately '''{{One_In_X|{{#expr: {Dose_Challenging_Baseline} * {Setting_Multiplier} * {Mindset_Multiplier} * {MentalHealth_Multiplier} }} }}'''.

A challenging experience is not necessarily harmful—many people report that difficult trips led to meaningful insights. However, without proper support, they can be distressing and occasionally lead to risky behavior.

Calculation: Baseline rates come from Johns Hopkins clinical trials where 30% experienced significant anxiety at high doses and 7% at moderate doses. These are adjusted by multipliers for set, setting, and mental health history.

RiskModel: Shrooms:PhysicalSafetyNarrative
Content: 
===Physical Safety===
{{#ifeq: {Setting_Safety}|High
|Psilocybin has '''extremely low physical toxicity'''. There are only 3 documented deaths from psilocybin toxicity in medical literature, and the lethal dose would require consuming roughly 1 kilogram of dried mushrooms. In your safe setting, physical risks are minimal. The main physical effects are mild: slight increases in heart rate and blood pressure, possible nausea, and dilated pupils.
|{{#ifeq: {Setting_Safety}|Moderate
|Psilocybin has '''extremely low physical toxicity'''—the drug itself is very unlikely to cause physical harm. However, in less controlled settings, the main physical risk is '''accidental injury''' from impaired judgment. 11% of people reporting challenging experiences said they put themselves or others at risk of physical harm. Stay in a safe place and have a sober person present.
|Psilocybin has '''extremely low physical toxicity''', but '''your setting increases risk of accidental harm'''. Impaired judgment in chaotic or public environments can lead to accidents, getting lost, or confrontations. 11% of challenging experience reports involved risk of physical harm. Consider choosing a safer environment.
}}}}

Psilocybin's therapeutic index is approximately 1:1000 (compared to morphine at 1:70). Physical overdose is essentially impossible at recreational doses. The primary physical risks come from the environment, not the substance.

RiskModel: Shrooms:HPPDRisk
Content: 
===HPPD (Hallucinogen Persisting Perception Disorder)===
HPPD involves persistent visual disturbances (trails, halos, geometric patterns) after the drug has worn off. Prevalence estimates vary widely:
* Clinical trials with proper screening: '''0%''' reported HPPD (though up to 9% had transient, benign flashbacks)
* Survey of recreational users: '''4.2%''' reported persistent symptoms consistent with HPPD

Most cases are mild and do not significantly impair daily life. HPPD is '''not''' psychosis—people with HPPD know their perceptions are not real. Risk factors include heavy use, pre-existing anxiety, and use of other substances.

HPPD remains poorly understood. Earlier estimates suggested 1 in 50,000 users; more recent surveys suggest higher rates but most cases are subclinical.

RiskModel: Shrooms:MedicationWarning
Content: 
===Medication Interactions===
{{#switch: {Medication_Risk}
|Dangerous='''⚠️ CRITICAL WARNING:''' You indicated you take lithium. Seizures have happened to many people who combined lithium with psychedelics. '''Do not use psilocybin while taking lithium.'''
|Reduced_Effects=You indicated you take SSRIs or SNRIs. About half of people on these medications report weaker psychedelic effects, sometimes much weaker. This is generally safe, but: (1) Do not suddenly stop your medication to use psilocybin—this can cause serious withdrawal effects. (2) If you want to explore psilocybin therapy, discuss tapering with your doctor.
|Caution=You indicated a medication that requires caution. Consult a healthcare provider before combining with psilocybin. Do not use without medical guidance.
|No specific medication concerns identified. Standard safety precautions apply.
}}

Interactions between classic psychedelics and serotonergic antidepressants | PMC

Additional Considerations

Emergency Medical Treatment: Only 0.2% of past-year psilocybin users in one large survey sought emergency medical treatment, with a per-event risk of 0.06%. This is lower than most other recreational substances.

Integration: The days and weeks after a psilocybin experience are important. The brain shows increased neuroplasticity during this window. Many practitioners recommend journaling, therapy, or reflection to integrate insights from the experience.

Frequency: Unlike MDMA, psilocybin does not appear to cause neurotoxicity and tolerance develops rapidly (requiring 1-2 weeks between doses for full effects). However, frequent use is not recommended—most therapeutic protocols use only 1-3 sessions total.

Initially created by Claude.