This page shows what was measured, who it was measured in, and what that does not settle.
What Psilocin does in the body
The phosphate is also why mushrooms keep: psilocin oxidises readily and turns blue, which is the bruising seen on picked mushrooms.
Psilocybin carries a phosphate group that makes it stable in the mushroom and inactive at the receptor. In the body, phosphatase enzymes strip that group off, leaving psilocin — the same molecule as DMT with a hydroxyl added at the 4 position. Psilocin is what binds the 5-HT2A serotonin receptor. The conversion is so complete that in a controlled pharmacokinetic study no psilocybin at all could be found in plasma or urine after an oral dose.
Why people take it. The active molecule produced when the body processes psilocybin.
What happened in people
In eight volunteers, blood level, brain-target binding and felt intensity rose together.
✓ Reviewed first-read answer
Where this came from
A person wrote this and a reviewer approved it against this exact record. It carries no effect size.
A reviewer approved this against this record. The reviewed-claim record carrying the exact population and effect size does not exist yet.
No source is stored against this line.
The limit that matters most
Showing one central target does not explain every later psychological or clinical effect.
Where it acts
Cortical 5-HT2A receptors, where positron emission tomography measured occupancy of up to 72% after a single oral psilocybin dose
Kind of result
A number that stands in for health
Supervision
RNAWiki has not recorded a supervision or regulatory status for this substance.
What the registries record it as
The substance registry classes this as chemical.
FDA substance registry · CMS88KUW0G · read 2026-08-29
Where each sentence above came from
A person wrote this explanation into the record, with the studies named in the path below.
A reviewer approved this sentence against this exact record and its sources.
The limit a reviewer approved as the one that matters most here.
The four opening statements run to 117 words.
Words this page uses
Four words worth knowing first
Chosen from what this page shows, with each one explained before the word it depends on.
Protein
A protein is a folded chain your body builds to do a specific job.
A picture of it, and where the picture fails
A protein is like a tool bent into one shape for one task.
Where that stops being true. A tool keeps its shape. A protein can change shape and stop working.
What people get wrong. Protein in food and a protein in the body are related but not the same thing.
A polymer of amino acids folded into a defined structure that determines its function.
Enzyme
An enzyme is a protein that speeds up one chemical change.
A picture of it, and where the picture fails
An enzyme is like a machine on a production line doing one cut.
Where that stops being true. A machine is switched on and off by a person. Enzymes are controlled by the cell.
What people get wrong. Enzymes are thought to be used up. They are not; they work again and again.
A catalytic protein that lowers the activation energy of a specific reaction.
Receptor
A receptor is a part of a cell that a signal fits into.
A picture of it, and where the picture fails
A receptor is like a lock waiting for one key.
Where that stops being true. A lock either opens or does not. A receptor can be half-triggered, or worn out.
What people get wrong. Fitting a receptor is read as causing a benefit. It causes a step, and nothing more.
A protein that binds a specific ligand and converts that binding into a cellular response.
Pathway
A pathway is a chain of steps inside a cell, each one setting off the next.
A picture of it, and where the picture fails
A pathway is like a row of dominoes.
Where that stops being true. Dominoes fall one way. Pathways loop back and can switch themselves off.
What people get wrong. Changing one step is read as changing the outcome. Other steps often absorb it.
An ordered series of molecular interactions producing a defined cellular change.
What happened in people◇Read from sources, not yet reviewed
What was measured, goal by goal
One row for each goal a registered study measured something for. One column for each kind of thing that could be measured.
Registered studies list 6 outcome measures that RNAWiki could read. A registered study says what someone planned to measure. It does not say what they found. 0 of the matched studies tested this substance, and 0 posted a result.
There is no single score. A strong test result and a weak life result are different facts.
Goals down the side, kinds of measurement across the top. Each cell says what kind of thing was registered, not what was found.
Goal
Life outcome
What a body can do
How a person feels
A test result
A step in the body
Harms
How long
Who was studied
Mood
∅Nothing in the sources checkedNo registered study lists a life outcome for this goal.
∅Nothing in the sources checkedNo registered study lists a performance measure for this goal.
…Waiting for a reviewer1 registered symptom measure.
∅Nothing in the sources checkedNo registered study lists a test result for this goal.
∅Nothing in the sources checkedNo registered study lists a body-step measure for this goal.
—Not recordedHarms were not a registered measure for this goal.
—Not recordedNo finished study window is recorded.
…Waiting for a reviewerWho was studied is listed further down the page.
Which registered measures put each goal on this table
Mood
depression scores; anxiety scores
Sorted by fixed word lists, version v1. A name the rules do not recognise stays unsorted rather than moving to the nearest column.
What each mark on this table means
∅ Nothing in the sources checked
No registered study lists a life outcome for this goal.
… Waiting for a reviewer
1 registered symptom measure.
— Not recorded
Harms were not a registered measure for this goal.
What happened in people◇Read from sources, not yet reviewed
What happened in people
Each card is one study: the exact question it asked, who was in it, and whether it showed what it set out to show.
Relationship between cerebral 5-HT2A occupancy, plasma psilocin and subjective psychedelic intensity
✓ The study showed what it set out to show
Who was studied
Madsen et al. 2019 [11C]Cimbi-36 PET occupancy study (Copenhagen)
How many people
8
Study design
Human PET occupancy study
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Dose-related occupancy up to 72%; plasma psilocin and occupancy conformed to a single-site binding model; subjective intensity correlated with both
Repeated elsewhere
Unreplicated
What this does not prove. Meeting one endpoint in one population does not carry to other goals or other people.
The limits of this study, and where it came from
Main limit. Eight participants across a 3-30 mg dose range, so each dose level is represented by very few scans. A correction to the published paper appeared in the same volume.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Delivered as psilocybin — oral capsule in trials, or mushroom material outside them
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
Pharmacokinetics and safety of psilocin after escalating oral psilocybin at 0.3, 0.45 and 0.6 mg/kg
✓ The study showed what it set out to show
Who was studied
Brown et al. 2017 escalating-dose pharmacokinetic study (Wisconsin)
How many people
12
Study design
Open-label pharmacokinetic study
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Linear psilocin pharmacokinetics across the twofold dose range; elimination half-life 3 h (SD 1.1); renal clearance of intact psilocin under 2% of total; no psilocybin detected in plasma or urine
Repeated elsewhere
Replicated
What this does not prove. Meeting one endpoint in one population does not carry to other goals or other people.
The limits of this study, and where it came from
Main limit. Open-label with no control arm and 12 participants. Doses of 0.6 mg/kg exceed likely therapeutic doses; no serious physical or psychological events occurred, which is a safety observation in a small prepared sample rather than a safety estimate.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Delivered as psilocybin — oral capsule in trials, or mushroom material outside them
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
RNAWiki holds 2 written-up human studies for this substance, each with the question it asked.
How we know it
Each card names the study, the number of people and what the study set out to measure.
What this does not prove
These summaries were written by a person and have not been signed off as reviewed claims.
Why it matters
A study that failed is as informative as one that worked, and both are here.
What we still do not know
No reviewed claim exists, so no exact population, effect size or interval is published yet.
What happened in people◇Read from sources, not yet reviewed
How close this is to real life
The top step is something a person would feel or care about. The bottom is a guess from software. Filled steps are where evidence exists for this substance.
□Living longer, or avoiding a major eventNo evidence recorded. Death, a heart attack, a stroke, a hospital stay.No registered study measures this.
□What a body can do day to dayNo evidence recorded. Walking, dressing, breathing, recovering.No registered study measures this.
□Measured performanceNo evidence recorded. How much was lifted, how far was run, how fast.No registered study measures this.
■Symptoms and quality of lifeEvidence recorded. Pain, tiredness, mood, sleep, as the person rated it.1 registered measure of this kind.
□A number that stands in for healthNo evidence recorded. Cholesterol, blood sugar, bone density. A stand-in, not the thing itself.No registered study measures this.
■A step measured inside a personEvidence recorded. Something measured in human tissue or human cells.A human record sits on the stored organism ladder.
■AnimalsEvidence recorded. Mice, rats, dogs. Useful for ideas, not proof about people.Stored records in Mouse. A result in animals says what to test next. It does not say what happens in people.
□Cells in a dishNo evidence recorded. Cells or chemistry on a bench, far from a whole body.No cell or bench record is stored.
□A guess from softwareNo evidence recorded. Nobody measured it. RNAWiki never publishes one as a finding.RNAWiki stores no prediction for this record. Software can suggest a link. RNAWiki does not publish one as a finding.
Higher on these steps means closer to something a person would feel. It does not mean better done.
What it changes in the body◇Read from sources, not yet reviewed
The path through the body
From what a person takes to what changes. A solid line is a step measured in people. A dashed line is a step nobody has measured that way.
Start
Psilocin
What a person takes: Delivered as psilocybin — oral capsule in trials, or mushroom material outside them.
The measurement behind this step
There is no psilocin product. The delivery system is the prodrug: a phosphate ester stable enough to formulate and to survive in dried fungal tissue, converted to the active compound by the recipient's own phosphatases. That design is the mushroom's, not a pharmacologist's, and it happens to solve the formulation problem that psilocin's oxidative instability would otherwise create.
Getting in
Arrives as psilocybin, not as itself
Every clinical dose and every mushroom delivers the phosphate form. Psilocin as such is not what anyone swallows.
╌╌Described, with no measurement named. No measurement is named for this step, so it is drawn as an unconfirmed link.
The measurement behind this step
Oral psilocybin, 3 to 30 mg in the PET occupancy study and 0.3 to 0.6 mg/kg in the pharmacokinetic study. Mushroom material additionally contains baeocystin and norbaeocystin, whose contribution has not been characterised in humans.
The phosphate is stripped off before absorption completes
Enzymes remove the phosphate group so completely that no psilocybin at all can be found in blood or urine afterwards.
──Measured in people. Written by a person from the study named beside the step. Not signed off as a reviewed claim.
The measurement behind this step
Dephosphorylation by alkaline phosphatase and non-specific esterases in the gut wall and liver. In 12 healthy adults given up to 0.6 mg/kg, no psilocybin was detected in plasma or urine by validated LC-MS/MS.
The free molecule crosses into the brain and binds the serotonin receptor that every classical psychedelic uses.
──Measured in people. Written by a person from the study named beside the step. Not signed off as a reviewed claim.
The measurement behind this step
Agonist at 5-HT2A with additional 5-HT1A and 5-HT2C activity. PET with [11C]Cimbi-36 measured dose-related cerebral occupancy up to 72%, with plasma psilocin and occupancy fitting a single-site binding model.
How intense the experience is rises with how much of the receptor is occupied and how much psilocin is in the blood, in the same people at the same time.
──Measured in people. Written by a person from the study named beside the step. Not signed off as a reviewed claim.
The measurement behind this step
Subjective psychedelic intensity correlated with both 5-HT2A occupancy and plasma psilocin, and with questionnaire scores. Time-concentration curves varied between individuals while the concentration-effect association held, which is why plasma level rather than administered dose is the better predictor.
Cleared in hours, by conjugation rather than by the kidney
A three-hour half-life, mostly cleared by attaching a sugar group in the liver, with under 2% leaving unchanged in urine.
╌╌Described, with no measurement named. No measurement is named for this step, so it is drawn as an unconfirmed link.
The measurement behind this step
Elimination half-life 3 hours (SD 1.1), predominantly glucuronidation with a further oxidative route via monoamine oxidase to 4-hydroxyindole-3-acetic acid. Renal clearance of intact psilocin under 2% of total; clearance variation not predicted by body weight.
No suggested links are held for this record, so nothing is hidden from this path.
What we know
The record describes 5 steps from taking it to an effect in a person.
How we know it
Each step names the study behind it in the technical detail beside it.
What this does not prove
A change inside the body is a reason to look. It is not a result in a person.
Why it matters
A reader can see exactly where the chain stops being measured in people.
What we still do not know
No reviewed claim binds any of these steps to a named population.
What it would be like to take◇Read from sources, not yet reviewed
Felt, measured, or meaningful
Three different things that get called the same word. Registered studies measured all three, and mixing them is how a blood test becomes a health claim.
Felt
Things a person could notice without a test.
anxiety scores
Measured
Things only a test, a scale or a device shows.
No registered study measured anything of this kind.
Meaningful
Things that change how a life goes, not only a number.
No registered study measured anything of this kind.
A registered study says what someone planned to measure. It does not say what they found. A number moving is not the same as a life going better. The two are shown apart here.
Felt, but not shown to help. A person notices a change. No study showed it leads anywhere good.
Measured, but not felt. A number moves. The person notices nothing. Both can be true.
Measured, but not shown to matter. A number moves in the good direction. Nobody showed that lives went better.
Matters, but takes years. The result that counts may take longer than anyone would keep watching.
Names that fit none of the three (5)
functional connectivity
physiological effects
psychological effects
adverse effects
depression scores
These are harms, study-process measures, or names the rules did not recognise. They are shown rather than dropped.
What is missing or unclear◇Read from sources, not yet reviewed
Were people like you studied?
RNAWiki cannot tell whether a study fits you. It can show who was in it, and where the result stops carrying.
Who was studied
People similar to this profile were included.
Nobody takes psilocin directly in clinical research; participants take psilocybin. Mushrooms deliver both, plus baeocystin and other congeners.
Who is missing from the studies
Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.
Where the result stopped carrying
Weight-based dosing, used through much of the psilocybin trial literature, is not supported by the clearance data and has been superseded by fixed dosing
Assays measuring only free psilocin misdescribe the exposure and the terminal half-life, because the glucuronide conjugate hydrolyses back
This is a scope explorer, not a diagnosis engine.
It shows who was studied so you can see whether people similar to you were included.
RNAWiki cannot tell whether a study fits you. It can show who was in it.
What it would be like to take◇Read from sources, not yet reviewed
Why it might seem to do nothing
A real effect and a noticed effect are different things. These are the recorded reasons the two come apart.
It was studied for a different goal
The studies measured something else entirely.
On this record: Some registered studies measured things that match no goal on this page.
It was studied in different people
The people in the studies were not much like the reader.
On this record: Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.
The evidence may simply be wrong
Small early studies often do not hold up.
On this record: RNAWiki has not yet published a reviewed conclusion for this use.
Other reasons RNAWiki checked and found nothing for (10)
A different form was studied
The studied form is not the form on the shelf. Nothing in this record points to this reason.
There was nothing to correct
Where a level is already normal, topping it up may change nothing. Nothing in this record points to this reason.
Something else had to happen too
In the studies it was paired with training, a diet or another treatment. Nothing in this record points to this reason.
The change is too small to feel
A real change can still sit below what a person notices. Nothing in this record points to this reason.
Day-to-day swing hides it
Sleep, food, stress and time of day move most numbers more than this would. Nothing in this record points to this reason.
Not enough time yet
The studies ran longer than the person has waited. Nothing in this record points to this reason.
It was not taken as studied
Missed days change the result, and studies count them. Nothing in this record points to this reason.
Something else changed at the same time
Two changes at once cannot be told apart afterwards. Nothing in this record points to this reason.
The product may not be what it says
Contents of a sold product are not always what the label states. Nothing in this record points to this reason.
No recorded reason
RNAWiki has nothing stored that would explain it. Nothing in this record points to this reason.
None of these is a reason to take more. Taking more is not a step this page ever suggests.
What it would be like to take◇Read from sources, not yet reviewed
What taking it involves
The recorded facts about getting hold of it and using it. Nothing here is a suggestion about what you should do.
How it is supplied
Not available
❝ Quoted from a source
Where this came from
Copied from a source RNAWiki stored, with the source named.
Read from the recorded approval status.
No source is stored against this line.
Form and route
Delivered as psilocybin — oral capsule in trials, or mushroom material outside them
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
The form and route recorded on this substance.
No source is stored against this line.
Who oversees it
RNAWiki has not recorded a supervision or regulatory status for this substance.
❝ Quoted from a source
Where this came from
Copied from a source RNAWiki stored, with the source named.
No register row and no identity class settled the question.
No source is stored against this line.
What is in the pack
There is no psilocin product. The delivery system is the prodrug: a phosphate ester stable enough to formulate and to survive in dried fungal tissue, converted to the active compound by the recipient's own phosphatases. That design is the mushroom's, not a pharmacologist's, and it happens to solve the formulation problem that psilocin's oxidative instability would otherwise create.
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
Recorded notes on how this is sold and what that means for what is in the pack.
No source is stored against this line.
Where it is registered
Regulatory records are listed in the technical disclosure at the foot of this page.
# Counted from records
Where this came from
A count of rows RNAWiki holds. It describes our records, not your body.
Register entries are stored per jurisdiction and shown with their dates.
No source is stored against this line.
Why people stop
Not recorded.
∅ Nothing recorded
Where this came from
RNAWiki holds nothing here and says so rather than guessing.
No record of why people stopped taking it is stored for this substance.
No source is stored against this line.
What it would be like to take◇Read from sources, not yet reviewed
What can go wrong
Sorted by where each line came from. A regulator's label and a report somebody sent in are not the same kind of fact.
·Worth asking a clinician aboutWritten into the record from the studies named on this page
In the escalating-dose pharmacokinetic study, no serious physical or psychological events occurred at doses up to 0.6 mg/kg — above the likely therapeutic range — in 12 prepared volunteers receiving 6 to 8 hours of preparatory counselling and 24 hours of monitoring. Renal clearance of intact psilocin under 2% of total supports no dose reduction in mild to moderate renal impairment. The acute effects and their duration follow the 3-hour half-life. Everything else on this record's safety profile belongs to the psilocybin page, because psilocin has never been administered to humans as such in a controlled study.
Nobody counted how many people took this and were fine, so this cannot be turned into a rate.
Over a long time. No completed tested study window is recorded, so long-term effects are not established by the registry record.
Groups the studies covered thinly. Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.
What is missing or unclear∅Nothing found in the sources checked
Does the exact form matter?
Evidence belongs to the exact thing that was tested. A different salt, a different mixture or a different preparation is a different question.
The form that was studied
Delivered as psilocybin — oral capsule in trials, or mushroom material outside them
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
The form used in the studies cited on this page.
No source is stored against this line.
What is sold
The delivery system is the prodrug: a phosphate ester stable enough to formulate and to survive in dried fungal tissue, converted to the active compound by the recipient's own phosphatases. That design is the mushroom's, not a pharmacologist's, and it happens to solve the formulation problem that psilocin's oxidative instability would otherwise create.
✎ Source-linked record
Where this came from
A person wrote this into the record with the study named beside it. No reviewer has signed it off.
Recorded notes on which forms are sold and how they compare.
No source is stored against this line.
Evidence carries across two names for one substance. It does not carry across a salt, a mirror form or a mixture.
What it would be like to take◇Read from sources, not yet reviewed
What you could measure
This one is decided with a clinician, so this section holds questions to ask rather than a plan to run.
RNAWiki could not confidently classify this substance, so no self-experiment plan is offered.
Questions worth asking
Which of the trials of Psilocin studied people like me?
What was measured, and for how long?
Was the result a laboratory value or a health outcome?
What would we watch for, and when would we stop?
Tracking can show whether something changed for you. It cannot show what caused it.
RNAWiki records evidence. It does not say whether this substance is right for you.
What is missing or unclear◇Read from sources, not yet reviewed
Claims that go past the evidence
Things said about this substance that sound reasonable, and the exact step that is missing between the evidence and the claim.
✗Goes past the evidence
That 5-HT2A occupancy explains durable clinical outcomes in depression trials, rather than the acute intensity it was measured against
Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.
The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.
What would change this
A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.
RNAWiki has not yet published a reviewed conclusion for this use.
✗Goes past the evidence
That psilocin's 5-HT1A and 5-HT2C activity contributes nothing to the experience — no human study has isolated them
Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.
The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.
What would change this
A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.
RNAWiki has not yet published a reviewed conclusion for this use.
✗Goes past the evidence
That mushroom material delivers a psilocin exposure equivalent to a weighed psilocybin dose; content varies and other congeners are present
Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.
The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.
What would change this
A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.
RNAWiki has not yet published a reviewed conclusion for this use.
✗Goes past the evidence
That the metabolite is unscheduled because the regulation does not contain the word "psilocin"; it is listed as "Psilocyn"
Why it sounds right. It follows from something real on this page: a body step, an animal result or a related finding.
The missing step. Nobody measured this in people for this use, or the study that did measure it did not show it.
What would change this
A study in people, for this exact use, measuring this exact thing, that a reviewer signs off.
RNAWiki has not yet published a reviewed conclusion for this use.
What is missing or unclear◇Read from sources, not yet reviewed
What nobody knows yet
Open questions, each with why it is open and what would close it.
How much did people take in the studies?
The sources RNAWiki checked hold nothing for this field.
Why it matters. A result belongs to an amount. Without the amount the result floats free.
What would answer it
A stored source that records it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
How fast does the body clear it?
The sources RNAWiki checked hold nothing for this field.
Why it matters. Without this, nothing on this page can say how long anything lasts.
What would answer it
A stored source that records it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Missing populations
Which groups were under-represented in the studies has not been recorded.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Missing long-term data
No completed tested study window is recorded.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
No reviewed conclusion
RNAWiki has not yet published a reviewed conclusion for this use.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Missing interaction studies
No interaction was found in the registers checked. Not finding one is not the same as showing there is none.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Formulation uncertainty
Several salts, forms or products of Psilocin are recorded. Results from one form may not transfer to another.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
Mechanism not reviewed
No reviewed mechanism story exists for this substance.
Why it matters. Recorded by the evidence model as a gap on this record.
What would answer it
A study that measures it, and a reviewer to sign it off.
Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.
What happened in people◇Read from sources, not yet reviewed
Check any of this yourself
Every line above traced back to the study it came from. This is the technical layer, and the vocabulary changes here.
Every line above can be traced to the study named beside it. Follow the link and read it.
Occupancy, plasma level and subjective intensity all on one curve
In plain words
Eight volunteers were scanned before and after taking psilocybin. How much of the 5-HT2A receptor was occupied, how much psilocin was in their blood, and how intense the experience felt all rose together and fitted a single binding model.
What was measured
Cerebral 5-HT2A occupancy by [11C]Cimbi-36 PET, plasma psilocin concentration and subjective intensity, measured concurrently in 8 volunteers across 3-30 mg
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Madsen et al. scanned eight healthy volunteers with the 5-HT2A agonist radioligand [11C]Cimbi-36 — one baseline scan and one or two further scans on the same day after a single oral dose of psilocybin between 3 and 30 mg. Occupancy was calculated as the percentage change in cerebral 5-HT2A binding from baseline, and subjective psychedelic intensity and plasma psilocin were measured during the scans. Psilocybin intake produced dose-related 5-HT2A occupancies up to 72%; plasma psilocin levels and occupancy conformed to a single-site binding model; and subjective intensity correlated with both occupancy and psilocin level as well as with questionnaire scores. The authors note that psilocin time-concentration curves varied between individuals but that psilocin levels remained closely associated with the psychedelic experience — which is the practically important finding for dosing in trials. A correction to the paper was published in the same volume.
Written into the record, not signed off as a reviewed claim
No psilocybin reaches the circulation at all
In plain words
In a controlled pharmacokinetic study, psilocybin could not be detected in plasma or urine after an oral dose. Conversion to psilocin is complete before absorption is finished.
What was measured
Plasma and urine psilocybin and psilocin concentrations, elimination half-life, renal clearance fraction and dose-linearity across 0.3-0.6 mg/kg, n=12
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Brown et al. gave sequential escalating oral doses of psilocybin at 0.3, 0.45 and 0.6 mg/kg to 12 healthy adults at roughly monthly intervals in a controlled setting, with 24-hour monitoring and blood and urine sampling assayed by validated LC-MS/MS for both psilocybin and psilocin. No psilocybin was found in plasma or urine. Psilocin pharmacokinetics were linear across the twofold dose range, with an elimination half-life of 3 hours (SD 1.1). Renal clearance of intact psilocin accounted for less than 2% of total clearance, and an extended elimination phase in some subjects suggested hydrolysis of the psilocin glucuronide. Variation in psilocin clearance was not predicted by body weight — a finding with direct consequences, since it undercuts the rationale for weight-based dosing. Simulation suggested a fixed 25 mg oral dose approximates the exposure of 0.3 mg/kg, which is the basis for the fixed doses used in current trials.
Written into the record, not signed off as a reviewed claim
Weight-based dosing is not supported by the clearance data
In plain words
Psilocybin trials have often dosed by body weight. The pharmacokinetic study found that body weight did not predict how fast psilocin was cleared.
What was measured
Relationship between body weight and psilocin clearance, and simulated fixed-dose equivalence to weight-based dosing
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Brown et al. report that variation in psilocin clearance was not predicted by body weight, and that simulation of fixed doses using the fitted pharmacokinetic parameters suggested an oral dose of 25 mg would approximate the exposure of a 0.3 mg/kg dose. That is a direct empirical argument against milligram-per-kilogram dosing for this compound: if weight does not explain clearance variation, weight-based dosing adds a scaling step without reducing exposure variability. Current clinical programmes use fixed doses, and this study is the pharmacokinetic basis for that choice. The finding also means that historical trials using mg/kg dosing and modern trials using fixed doses are more comparable than the different units suggest, provided the conversion is applied.
Written into the record, not signed off as a reviewed claim
The prodrug relationship, and what the phosphate is for
In plain words
Psilocybin is psilocin with a phosphate group attached. The phosphate makes the molecule stable and inactive; enzymes in the body remove it, and only then does the drug work.
What was measured
Dephosphorylation of psilocybin to psilocin and the subsequent glucuronidation and oxidative metabolic routes
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Psilocybin is the 4-phosphoryloxy ester of psilocin, dephosphorylated in vivo by alkaline phosphatase and non-specific esterases to yield the free 4-hydroxy compound. The ester is not appreciably active at 5-HT2A, which is why the Madsen occupancy study correlates effects with plasma psilocin rather than with the administered compound. The phosphate serves the fungus rather than the pharmacologist: psilocin's free 4-hydroxy group oxidises readily, and the blue discoloration of bruised or picked Psilocybe mushrooms is that oxidation made visible, so the phosphate ester is the storage form. Psilocin is further metabolised by glucuronidation and by monoamine oxidase to 4-hydroxyindole-3-acetic acid, which was the analyte measured alongside psilocin in the earliest human pharmacokinetic work.
Written into the record, not signed off as a reviewed claim
Scheduled under a spelling almost nobody uses
In plain words
The federal drug schedule lists it as "Psilocyn", not psilocin, at code 7438 — immediately after psilocybin at 7437. Searching the regulation for the ordinary spelling returns nothing.
What was measured
Listing of psilocybin and psilocin as separate Schedule I entries under DEA codes 7437 and 7438
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
The current text of 21 CFR 1308.11(d) lists, in sequence, "(29) Psilocybin 7437" and "(30) Psilocyn 7438". The archaic spelling is a genuine practical trap: a search of the regulation for "psilocin" returns no match, which can lead a reader to conclude the metabolite is unscheduled when in fact it is Schedule I in its own right and has been since the Controlled Substances Act. Both compounds are separately listed, so possession of either is separately covered — a point that matters for the semi-synthetic prodrugs such as 4-acetoxy-DMT that hydrolyse to psilocin, and for the mushroom material itself, which contains both.
Source
21 CFR 1308.11(d)(29) and (d)(30), current eCFR text
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
verified
Review state
Written into the record, not signed off as a reviewed claim
Occupancy correlating with intensity does not make occupancy the whole mechanism
In plain words
Receptor occupancy tracks how intense the experience feels. That establishes 5-HT2A as necessary and central; it does not establish that everything downstream is explained by it.
What was measured
That 5-HT2A occupancy explains the durable clinical effects reported in psilocybin depression trials, rather than only the acute subjective intensity it was measured against
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Madsen et al. conclude that their findings "strongly support that stimulation of 5-HT2AR is a key determinant for the psychedelic experience", and the phrasing is careful. Eight participants, a correlation between three concurrently measured quantities, and a single-site binding fit establish that 5-HT2A occupancy is closely tied to acute subjective intensity. They do not establish that the therapeutic effects reported weeks later in depression trials are a function of that occupancy, nor that psilocin's 5-HT1A and 5-HT2C activity contributes nothing, nor that two people at the same occupancy have the same experience. The acute-intensity relationship is measured; the extension to durable clinical outcome is the inference, and it is the one the field most often makes silently.
Written into the record, not signed off as a reviewed claim
A three-hour half-life behind a six-hour session
In plain words
Psilocin is cleared with a half-life of about three hours, which is why a psilocybin session lasts most of a working day rather than most of a night.
What was measured
Psilocin elimination half-life, extended elimination phase and renal clearance fraction across 12 healthy adults
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
The elimination half-life of psilocin was 3 hours with a standard deviation of 1.1 in the Wisconsin study, and an extended elimination phase appeared in some subjects consistent with hydrolysis of the glucuronide conjugate. That figure fixes the practical shape of a clinical session: a monitored period of six to eight hours covers roughly two to three half-lives, which is the pharmacokinetic justification for the session length used across the psilocybin trial literature. Renal clearance of intact psilocin was under 2% of the total, which the authors note means no dose reduction is indicated for mild to moderate renal impairment — a specific, checkable clinical statement derived from a pharmacokinetic parameter rather than from a safety study.
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What is not here
5 questions this page could not answer
These sections were prepared and left out because there was nothing to put in them. They are listed rather than hidden, so the gaps in this record are visible.
How long anything takes — found nothing in the sources checked.
What it may clash with — found nothing in the sources checked.
Other ways to the same goal — found nothing in the sources checked.
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The record as stored
The full record, for auditing
Everything above is built from what is below. This layer keeps the technical vocabulary, record identifiers and every stored row, so a reader who wants to check the page can.
The older medicine-wide conclusion held in this record
Written for a clinical reader, and about the medicine as a whole rather than about one indication, population and set of trials. RNAWiki does not treat it as a programme conclusion and no reviewer has signed it off in that form. It is here word for word because it is what the record holds.
The molecule that does the work: psilocybin is a phosphate ester with essentially no 5-HT2A activity of its own, and in eight volunteers scanned by PET, plasma psilocin, cerebral 5-HT2A occupancy up to 72%, and subjective intensity all tracked one another through a single-site binding model.
Recorded evidence blocks (8)
Q1
What did Psilocin's largest trial (60 people) and its longest (3.1 years) measure?
60 people in Psilocin's largest registered study, 3.1 years in its longest registered window, measuring Functional Connectivity. ClinicalTrials.gov · 2026-09-01
2 phase1, 1 early phase1, 1 phase2; NCT05317689; 2025-07; no ageing endpoint recorded. Last human test completed 2025, NCT06746441.
Interpretation These counts include studies where Psilocin was a comparison treatment, a background treatment or an exposure in an observational study, and the longest window may be a planned end date. Trial roles have not yet been classified for this record.
Show the evidence
phase1
2
early phase1
1
phase2
1
Last recorded human testNCT06746441
2025-07-30
recorded 2026-09-01 · last checked 2026-09-04
Q2
From mouse to human: where has Psilocin shown lifespan?
Interpretation Functional Connectivity — the recorded outcome words.
Show the evidence
mouse
lifespan
humanNCT04501653
mechanism-only; Functional Connectivity; 4
recorded 2026-09-01 · last checked 2026-09-04
Q3
More Psilocin was worse in human: at what point?
U-shaped in human: "DOM, mescaline, and psilocin reduced locomotor activity at high doses and influenced rearings, an exploratory behaviour, in a characteristic inverted U-shaped dose-response function." Europe PMC · dose-response search · 2025-01-15
5 recorded sentences naming Psilocin; U-shaped, biphasic, dose-response
Show the evidence
U-shapedPMID 36874002
"DOM, mescaline, and psilocin reduced locomotor activity at high doses and influenced rearings, an exploratory behaviour, in a characteristic inverted U-shaped dose-response function."
biphasicPMID 39812743
"Psilocin's biphasic concentration-time profiles demonstrates fast and extensive disposition with an apparent distribution volume of 505-1267 L and a terminal half-life of 1.23-4.72 h."
dose-responsePMID 28074670
"During the last few years, psilocybin and psilocin have gained therapeutic relevance but considerable physiological variability between individuals that can influence dose-response and toxicological profile has been reported."
biphasic
PMID 20007669
"The kinetics of psilocin glucuronidation by UGT1A9 was more complex and may be best described by biphasic kinetics with both intermediate (K(m1) = 1.0 mM) and very low affinity components."
PMID 882579
"Selected low (0.71 mg/kg) or high (5.70 mg/kg) doses of psilocin also had a biphasic dose-response effect on startle comparable in magnitude to equimolar doses of psilocybin."
recorded 2025-01-15 · last checked 2026-09-04
Q4
Could one person measure Psilocin's effect on functional connectivity?
Functional connectivity: measured in Psilocin's trials.
Interpretation functional connectivity is the recorded endpoint.
Show the evidence
biomarkers
functional connectivity; 2026-09-01
physiological effects; 2026-09-01
psychological effects; 2026-09-01
adverse effects; 2026-09-01
depression scores; 2026-09-01
anxiety scores; 2026-09-01
human trials at or under30
3
Not recorded for this substance
a recorded half-life
smallest human trial
10; NCT06035900; PHASE1; the smallest recorded human enrolment at or below 30; the registry states no direction of its result; COMPLETED
Q5
Which of adverse effects, anxiety scores and depression scores did Psilocin's trials measure?
adverse effects, anxiety scores and depression scores lead 6 outcome terms across Psilocin's trials. ClinicalTrials.gov · 2026-09-01
Interpretation adverse effects, depression scores and anxiety scores follow.
Show the evidence
functional connectivity
1
physiological effects
1
psychological effects
1
adverse effects
1
depression scores
1
anxiety scores
1
recorded 2026-09-01 · last checked 2026-09-04
Q6
What will the one ongoing trial of Psilocin report, and when?
ClinicalTrials.gov — US Government work · Europe PMC — metadata only, under the recorded legal gate · derived from this page's own recorded fields; no external licence
✗ required summary fields resolved: 4 required field(s) not terminal: Why people use it, Best-supported result, Biggest unanswered question, Human evidence
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✓ source coverage passed: 4 source rows
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