Psilocybin half-life
Psilocybin is a prodrug-adjacent story: the page is most useful when read beside psilocin and duration context.
Effects, impairment, and testing
None of these can be calculated from half-life alone.
Psychological effects and functional recovery are not represented by a single psilocybin or psilocin decline line.
Half-life versus durationEven after subjective effects appear to resolve, the profile value cannot establish judgment or readiness for ordinary activities.
Safety boundaryStudies and laboratories define analytes differently across specimens, so the profile does not assign a window.
Why testing is differentEvery curve begins at 100%. No dose or measured body concentration is assumed.
X-axis: elapsed time. Y-axis: modeled percentage of the relative starting point remaining. This is a mathematical visualization, not a personal concentration estimate.
What a careful reader should notice first
The curve should not be mistaken for a full description of psychological effects or metabolite-driven exposure.
Source angle
Look for whether a study reports psilocybin, psilocin, or both, and how route and sampling were handled.
Do not use it for
Do not use this page to estimate intensity, psychological duration, safety, or impairment.
Best next step
Compare with DMT and LSD, then read active-metabolite and duration guides.
Psilocybin: evidence and interpretation notes
The chart actually follows psilocin
Psilocybin is rapidly transformed into psilocin, the pharmacologically active metabolite measured in most human pharmacokinetic studies. Brown and colleagues studied 12 healthy adults after oral psilocybin and found no measurable psilocybin in plasma or urine; the reported three-hour elimination half-life belonged to psilocin. The model label makes that analyte substitution explicit.
This is not a technicality. Calling the curve simply “psilocybin” without identifying psilocin would imply that the administered prodrug and measured circulating compound were interchangeable.
| Evidence source | What it contributes | Important limit |
|---|---|---|
| Brown healthy-adult study | Direct 12-participant psilocin measurements and a three-hour mean | It was a small, open-label, controlled cohort |
| 2025 systematic review | Nineteen publications, 12 unique datasets, analyte differences, and a 1.23-to-4.72-hour range | Included studies used different assays and definitions of unconjugated, conjugated, or total psilocin |
| PubChem psilocybin record | Identity of the administered prodrug | It does not establish the psilocin half-life used here |
The systematic review explains why assays matter
The 2025 review found that most studies measured unconjugated psilocin, while some reported conjugated or total concentrations. Across the included clinical datasets, terminal psilocin half-lives ranged from 1.23 to 4.72 hours. The review also described biphasic concentration-time profiles and broad distribution estimates.
HalfLifeDB keeps the direct three-hour study estimate instead of pooling unlike measurements. A rigorous combined model would need access to study-level concentration data, assay definitions, routes, and sampling schedules. A simple average of published half-lives would hide those differences.
What a psilocin curve leaves unanswered
The modeled decline cannot predict psychological intensity, subjective duration, therapeutic response, impairment, or safety. Those outcomes involve receptor pharmacology, setting, individual response, and study protocol in addition to concentration.
This page is most useful as an analyte-literacy example: the name people search is psilocybin, the human plasma curve usually follows psilocin, and the evidence only becomes readable when that conversion is stated plainly.
InterpretationReading the curve and its category context
Reading this curve
HalfLifeDB uses 3 h as a representative input for Psilocin after oral psilocybin. In the simplified model, about 0.4% remains after 24 hours and about 3% remains after five half-lives, or roughly 15 h.
This is a short curve. The modeled amount changes noticeably over the same day, while effects, metabolites, and safety questions can still follow a different timeline. The curve is relative: it does not estimate a person's measured concentration, effects, impairment, or time to clearance.
psychedelic context
Psychedelic duration is shaped by pharmacodynamics as well as pharmacokinetics, so subjective effects may not track a simple elimination curve.
- The curve does not predict psychological effects or functional safety.
- Metabolites and downstream receptor activity are not separately modeled.
- Published estimates may come from small or specialized study populations.
ComparisonTimeline checkpoints and nearby profiles
Psilocybin timeline checkpoints
| Elapsed time | Modeled remaining | Reading note |
|---|---|---|
| 6 h | 25.0% | Long-tail portion of the model |
| 12 h | 6.25% | Low modeled remainder, not a clearance guarantee |
| 24 h | 0.39% | Low modeled remainder, not a clearance guarantee |
| 2.0 days | 0.00% | Low modeled remainder, not a clearance guarantee |
| 3.0 days | 0.00% | Low modeled remainder, not a clearance guarantee |
Nearby profiles by half-life
These entries sit near Psilocybin within the psychedelic group when sorted by representative half-life. That makes them curve comparisons, not statements about equal potency, effects, or risk.
EvidencePharmacokinetic inputs and source trail
Pharmacokinetics at a glance
| Representative half-life | 3 h |
|---|---|
| Modeled analyte or phase | Psilocin after oral psilocybin |
| Curve type | Normalized, first-order decline |
Selection note: The linked human study measured psilocin, the active metabolite formed after oral psilocybin, and reported a 3-hour elimination half-life.
Sources and evidence context
A linked record is not automatically proof of the displayed value. Study, labeling, review, and compound identity sources serve different purposes; notes below identify limitations when they are known.
- Research abstract Brown RT et al. Pharmacokinetics of escalating doses of oral psilocybin in healthy adults (2017).Open-label study in 12 healthy adults; direct support for the three-hour psilocin half-life after oral psilocybin.
- Research abstract Clinical pharmacokinetics of psilocin after psilocybin administration: systematic review (2025).Systematic review of 19 publications covering 12 unique clinical datasets and a 1.23-to-4.72-hour terminal psilocin range.
- Identity record PubChem Compound Summary: Psilocybin.Psilocybin identity record; it does not establish the psilocin value modeled by the chart.
BoundariesWhat this page cannot answer and where to continue
What this page does not answer
- It does not estimate impairment, intoxication, or fitness to drive.
- It does not predict urine, blood, saliva, or hair test results.
- It does not model repeated exposure, tolerance, withdrawal, or interactions.
- It does not replace clinician, pharmacist, toxicologist, or emergency guidance.
Continue with context
- All substance profiles
- Browse the psychedelic group
- Compare this curve
- Clearance and volume of distribution
- Bioavailability, route, and formulation
- Active metabolites and parent compounds
- First-order vs nonlinear kinetics
- Detection windows vs half-life
- Reading labels and source quality
Read the medical disclaimer, methodology, and research standards before using the model for comparison.