This page shows what was measured, who it was measured in, and what that does not settle.
What Mescaline does in the body
Nothing. Mescaline is the only classic psychedelic in this group with no modern randomised trial at all
Mescaline reaches the same serotonin receptor as LSD and psilocybin, but it belongs to a different chemical family — it is built on the same skeleton as amphetamine, with three methoxy groups added to the ring. Those groups are what convert a stimulant scaffold into a psychedelic one. It is roughly a thousand times weaker than LSD by weight, so the amount needed is measured in hundreds of milligrams rather than micrograms, and the experience runs ten to twelve hours.
What happened in people
Agonism at 5-HT2A with roughly three orders of magnitude lower affinity than LSD, accounting for the milligram-scale active dose
✎ 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 recorded finding that sits closest to something a person would notice. Written into the record, not signed off, and it carries no population or interval.
That survey self-report from people who chose to take mescaline estimates a treatment effect
Where it acts
Cortical 5-HT2A receptors
Kind of result
The kind of result is not recorded
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 · RHO99102VC · read 2026-08-29
Its recorded molecular formula is C11H17NO3, weighing 211.26.
PubChem record · 4076 · read 2026-08-29
Where each sentence above came from
No recorded sentence describes the change this makes in a way that stands on its own. The page opens with what it is taken for instead, and the recorded explanation follows below.
Shown as the opening line on this page.
A limit recorded against this substance. Not signed off as a reviewed claim.
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.
Biomarker
A biomarker is a number from a test that stands in for something about health.
A picture of it, and where the picture fails
A biomarker is like a fuel gauge.
Where that stops being true. A gauge is wired to the tank. Many biomarkers are only loosely tied to health.
What people get wrong. A better number is read as a better life. Several medicines improved a number and helped nobody.
A measurable indicator used as a substitute for a clinical outcome of interest.
Placebo
A placebo is a dummy treatment given so the real one can be compared with it.
A picture of it, and where the picture fails
A placebo is like a blank control in an experiment.
Where that stops being true. A blank does nothing. People given a placebo often do get better.
What people get wrong. A placebo effect is read as imaginary. The improvement is measured and real.
An inactive intervention matched in appearance to the test intervention, used to control for non-specific effects.
Comparator
A comparator is whatever the treatment was measured against.
A picture of it, and where the picture fails
It is like the other runner in a race.
Where that stops being true. A race has one winner. A study can show both arms improved.
What people get wrong. Results are read without asking what the other group got. Beating nothing is not beating a treatment.
The control condition against which the experimental intervention is assessed.
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.
Self-reported improvement in depression, anxiety, PTSD, alcohol use disorder and drug use disorder after the most memorable mescaline experience
✓ The study showed what it set out to show
Who was studied
Naturalistic mescaline use survey (Agin-Liebes et al. / Uthaug et al.)
How many people
452
Study design
Retrospective anonymous online survey, not a trial
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
68 to 86% of respondents with a relevant history reported subjective improvement; Cohen's d 0.7 to 1.5 for acute-effect ratings between improvers and non-improvers
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. Self-selected sample, no control group, no verification of substance identity or dose, and recall of a single self-nominated "most memorable" experience. 9% reported craving; 1% reported psychological problems.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral — dried cactus material, a decoction, or the isolated salt
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
21 CFR 1307.31 — Native American Church exemption for non-drug ceremonial use of peyote (https://www.ecfr.gov/current/title-21/chapter-II/part-1307/section-1… · a recorded source, not a stored snapshot
What we know
RNAWiki holds 1 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 lifeNo evidence recorded. Pain, tiredness, mood, sleep, as the person rated it.No registered study measures this.
□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.
□AnimalsNo evidence recorded. Mice, rats, dogs. Useful for ideas, not proof about people.No animal record is stored.
□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
Mescaline
What a person takes: Oral — dried cactus material, a decoction, or the isolated salt.
The measurement behind this step
Taken by mouth in every documented context. Dried peyote buttons and San Pedro preparations deliver a dose that depends on the alkaloid content of that specific plant material, which varies with species, age and growing conditions, so the delivered dose from plant material is not knowable without an assay.
Getting in
Swallowed, as dried cactus or as the isolated alkaloid
Taken by mouth. Effects begin within an hour or two and continue for most of a day. Nausea and vomiting early in the experience are the rule rather than the exception.
╌╌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 administration of dried cactus material or mescaline salt. Onset within 45 to 90 minutes, peak at 2 to 4 hours, total duration 10 to 12 hours. Gastrointestinal upset early in the time course is characteristic and is attributed both to mescaline and to the other cactus constituents.
Distributes into the brain and is largely excreted unchanged
It reaches the brain and a large share of it leaves the body intact in urine rather than being broken down.
╌╌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
A substantial fraction of an oral dose is excreted unchanged in urine, with 3,4,5-trimethoxyphenylacetic acid as the principal metabolite from monoamine oxidase-mediated deamination. The long duration reflects slow clearance rather than slow receptor dissociation.
It reaches the same receptor as LSD but grips it about a thousand times less tightly, which is why the dose is a thousand times larger.
╌╌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
Agonist at 5-HT2A with additional 5-HT2C and 5-HT1A activity. The roughly thousand-fold lower affinity relative to LSD is the direct determinant of the milligram dose, and the mechanism is otherwise the same as the other classic psychedelics.
Cortical processing changes for ten to twelve hours
The same broad reorganisation the other psychedelics produce, sustained across most of a day.
──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
Gq-coupled 5-HT2A signalling in cortical pyramidal neurons, as with LSD, psilocin and DMT. Human functional imaging of mescaline specifically is very limited; the mechanistic account here is largely extrapolated from the better-studied compounds in the class, and this page marks that as extrapolation.
There is no trial endpoint to report. What exists is what people said afterwards in a survey.
╌╌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
No randomised clinical endpoint exists for mescaline. The available outcome data are retrospective self-reports from 452 survey respondents, in which 68 to 86% of those with a psychiatric history reported subjective improvement, with no control group and no verification of the substance taken.
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 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.
Members of the Native American Church, under a federal regulatory exemption for ceremonial peyote. Otherwise, people using peyote or San Pedro cactus or synthetic mescaline outside any medical or legal framework.
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
No modern randomised controlled trial of mescaline for any indication has been completed, which is the central fact about its evidence base
The mid-twentieth-century clinical literature predates randomisation, blinded outcome assessment and systematic adverse-event reporting, and cannot substitute for one
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
Oral — dried cactus material, a decoction, or the isolated salt
✎ 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
Taken by mouth in every documented context.
✎ 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. The rest of the recorded wording: Dried peyote buttons and San Pedro preparations deliver a dose that depends on the alkaloid content of that specific plant material, which varies with species, age and growing conditions, so the delivered dose from plant material is not knowable without an assay.
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
Nausea and vomiting early in the time course are characteristic. Acute effects include sympathomimetic changes — raised blood pressure, heart rate and pupil diameter — with a 10 to 12 hour course of perceptual and cognitive change. In the survey of 452 naturalistic users, 9% reported drug craving or desire, 1% reported legal problems, 1% reported psychological problems, and none reported seeking medical attention; that is self-report from a self-selected sample and should be read as such. As with the other classic psychedelics, personal or family history of psychosis is the risk that matters and there is no controlled data on it here. Mescaline does not produce physical dependence, and tolerance develops rapidly with repeated dosing.
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
Oral — dried cactus material, a decoction, or the isolated salt
✎ 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
A recorded note compares this form with the others that are sold. It is kept below, word for word.
§ A fixed RNAWiki sentence
Where this came from
Wording RNAWiki always uses, not a finding about this substance.
The recorded note, unchanged: Dried peyote buttons and San Pedro preparations deliver a dose that depends on the alkaloid content of that specific plant material, which varies with species, age and growing conditions, so the delivered dose from plant material is not knowable without an assay.
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 Mescaline 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 survey self-report from people who chose to take mescaline estimates a treatment effect
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 psilocybin and LSD trial results transfer to mescaline by class analogy, when the compounds differ by a thousand-fold in potency and by a factor of two in duration
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 peyote exemption extends to mescaline, San Pedro or ceremonial use outside the Native American Church
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 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 Mescaline 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.
No completed randomised controlled trial of mescaline exists
In plain words
LSD, psilocybin and MDMA all have modern randomised trials. Mescaline has none. The evidence is 1950s literature and two online surveys.
What was measured
Number of completed randomised controlled trials of mescaline for a clinical indication: zero
Effect estimate
No reviewed effect estimate exists for this record.
Limits
This entry records a failure.
From the source
Of the four classic psychedelics, mescaline is the only one with no completed modern randomised controlled trial for any clinical indication. The mid-twentieth-century literature is substantial but predates modern trial standards, randomisation, blinded outcome assessment and adverse-event reporting. The contemporary evidence consists of retrospective self-report surveys. This absence has a mundane explanation — mescaline's ten-to-twelve-hour duration, its lack of a commercial sponsor, its low potency relative to the compounds attracting investment, and the ethical and supply constraints around peyote — and no scientific one. What it means for a reader is that this page contains no efficacy claim, because there is no efficacy measurement to report.
Written into the record, not signed off as a reviewed claim
452 people answered a survey; that is the modern therapeutic literature
In plain words
Two studies of the same 452-person online survey found most respondents said their depression or anxiety improved. Everyone in it had chosen to take mescaline and chose to answer.
What was measured
That self-reported improvement in a self-selected online sample estimates a treatment effect — it estimates what people who liked the experience say about it afterwards
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
An anonymous online questionnaire of 452 adults reporting naturalistic mescaline use asked about self-reported mental health benefits. Among respondents reporting histories of depression, anxiety, PTSD, alcohol use disorder or drug use disorder, 68 to 86% reported subjective improvement following their most memorable mescaline experience. Those reporting improvement rated acute mystical-type, psychological-insight and ego-dissolution effects significantly higher than those who did not, with Cohen's d from 0.7 to 1.5. Between 35 and 50% rated the experience among the five most spiritually significant of their lives. A companion analysis of the same survey found most respondents used mescaline once a year or less, 74% for spiritual exploration or connection with nature, with 9% reporting craving, 1% legal problems, 1% psychological problems and none seeking medical attention. Every one of these numbers is retrospective self-report from a self-selected sample of people who chose to use the drug and chose to answer questions about it, with no control group and no verification of what was taken. The authors of both papers say so.
Written into the record, not signed off as a reviewed claim
The exemption protects a ceremony, not a molecule
In plain words
Federal regulation exempts ceremonial peyote use by the Native American Church from Schedule I. Mescaline itself, and San Pedro cactus, and synthetic mescaline, are not covered.
What was measured
Scope of the federal regulatory exemption for peyote
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
21 CFR 1307.31 states that the listing of peyote as a Schedule I controlled substance does not apply to the non-drug use of peyote in bona fide religious ceremonies of the Native American Church, and that members so using peyote are exempt from registration; anyone manufacturing or distributing peyote to the Church must register annually and comply with all other requirements. The exemption is written around a plant, a religious body and a ceremonial context. It does not cover isolated mescaline, other mescaline-containing cacti, or use outside that context. This is the same structural pattern as the DMT exemption upheld in Gonzales v. O Centro Espírita: an exception to enforcement granted on religious-freedom grounds, with the scheduling of the substance left entirely intact.
Source
21 CFR 1307.31, Native American Church, 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
Three orders of magnitude weaker than LSD, and that is a receptor fact
In plain words
An active mescaline dose is measured in hundreds of milligrams; an active LSD dose in tens of micrograms. The difference comes straight from how tightly each binds the receptor.
What was measured
5-HT2A receptor affinity of mescaline relative to LSD
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Mescaline is a 3,4,5-trimethoxyphenethylamine — the parent compound of the substituted-phenethylamine psychedelics including the 2C and DO series. Its affinity at 5-HT2A is roughly a thousand-fold lower than LSD's, which accounts directly for the difference in active dose without invoking any difference in mechanism. Duration is 10 to 12 hours, comparable to LSD and roughly double psilocybin. The practical consequence is that mescaline is not a plausible target for the microdosing and short-session formats being commercialised for other psychedelics, and that potency comparisons between psychedelics are meaningful only when normalised to receptor occupancy rather than to milligrams.
Written into the record, not signed off as a reviewed claim
Peyote is a slow-growing wild plant, and demand is a conservation question
In plain words
Peyote takes many years to reach a harvestable size and does not survive careless harvesting. Rising interest in mescaline is a supply pressure on a wild population that already supplies a religious community.
What was measured
That growing interest in mescaline can be met from cactus material without affecting a wild population that is also a protected religious supply
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Lophophora williamsii is a slow-growing cactus with a limited natural range in south Texas and northern Mexico; individual plants take years to reach maturity, and harvesting technique determines whether the root survives to regrow. The plant is the sacrament of the Native American Church, whose supply is legally protected and practically finite. San Pedro and related Trichocereus species grow far faster and are widely cultivated, and synthetic mescaline is chemically straightforward, so neither the ceremonial supply nor the wild population is a necessary source for research or for recreational demand. This is a resource claim rather than a pharmacological one, and it is on the page because a drug reference that discusses mescaline without it is describing a molecule and ignoring where it comes from.
This order is fixed in code and does not count clicks or time on the page.
What is not here
7 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.
What was measured, goal by goal — found nothing in the sources checked.
Felt, measured, or meaningful — found nothing in the sources checked.
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.
How this medicine reached us — found nothing in the sources checked.
What changed on this page — found nothing in the sources checked.
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 classic psychedelic with the longest documented human use and the thinnest modern evidence base: no completed randomised trial, a survey literature of 452 respondents, and a federal exemption that protects the cactus rather than the molecule.
Recorded evidence blocks (8)
Q1
What did Mescaline's largest trial (32 people) and its longest (2.3 years) measure?
32 people in Mescaline's largest registered study, 2.3 years in its longest registered window, measuring 5 Dimensions of Altered States of Consciousness (5D-ASC). ClinicalTrials.gov · 2026-09-01
2 phase1; NCT04227756; 2022-09-02; no ageing endpoint recorded. Last human test completed 2023, NCT04849013.
Interpretation These counts include studies where Mescaline 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.
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phase1
2
Last recorded human testNCT04849013
2023-03-27
recorded 2026-09-01 · last checked 2026-09-04
Q2
Mescaline was tested only in human — what did it show?
5 recorded entries; human; also "Mescaline 200mg", "Mescaline 400mg", "Mescaline 800mg"
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human
NCT04849013
Mescaline 100mg
NCT04849013
Mescaline 200mg
NCT04849013
Mescaline 400mg
NCT04849013
Mescaline 800mg
NCT04849013
Mescaline 800mg + Ketanserin 40mg
recorded 2026-09-01 · last checked 2026-09-04
Q4
More Mescaline 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 · 2023-02-16
5 recorded sentences naming Mescaline; U-shaped, biphasic, dose-response
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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."
biphasic
PMID 17922234
"Mescaline produced significant inhibitory effects on locomotion in low doses and a biphasic effect with the highest dose."
PMID 3569841
"A previously-reported biphasic pattern of effects of mescaline on shuttle avoidance was replicated and extended to 12 other hallucinogens of both phenylethylamine and indolealkylamine classes."
PMID 3747721
"Mescaline, in moderate to large doses, can induce biphasic--depressant followed by stimulant--effects on learnt and other performance of laboratory rodents."
dose-responsePMID 6817241
"Metergoline pretreatment shifted the LSD and DMT dose-response curves for pausing to the right by a factor of 2--3, but shifted the DOM and mescaline dose-response patterns to a much greater extent."
recorded 2023-02-16 · last checked 2026-09-04
Q5
Could one person measure Mescaline's effect on 5 dimensions of altered states of consciousness?
5 dimensions of altered states of consciousness: measured in Mescaline's trials.
5 dimensions of altered states of consciousness is the recorded endpoint.
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biomarkers
5 dimensions of altered states of consciousness; 2026-09-01
fmri resting state functional connectivity; 2026-09-01
altered states of consciousness; 2026-09-01
human trials at or under30
1
Not recorded for this substance
a recorded half-life
smallest human trial
16; NCT04849013; PHASE1; the smallest recorded human enrolment at or below 30; the registry states no direction of its result; COMPLETED
Q6
Which of 5 dimensions of altered states of consciousness, altered states of consciousness and fmri resting state functional connectivity did Mescaline's trials measure?
5 dimensions of altered states of consciousness, altered states of consciousness and fmri resting state functional connectivity lead 3 outcome terms across Mescaline's trials. ClinicalTrials.gov · 2026-09-01
3 terms in all.
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5 dimensions of altered states of consciousness
1
fmri resting state functional connectivity
1
altered states of consciousness
1
recorded 2026-09-01 · last checked 2026-09-04
Q7
Which 2 trials of Mescaline posted no result?
Posted no result
2 of 2 completed trials
Registrations
NCT04227756 and NCT04849013
Completion dates
oldest 2022-09-02; newest 2023-03-27
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Trial
NCT04227756
2022-09-02
NCT04849013
2023-03-27
Q8
At the median, Mescaline's trials enrolled 24 people — anything larger?
Median enrolment
24
Largest enrolment
32
Registered trials counted
2
Where it is registeredIdentifiers, relations and other names
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
✓ public claims reviewed: 0 reviewed claim(s); drafts are never rendered
✓ source coverage passed: 6 source rows
✓ no critical contamination: no quarantine open
✓ canonical metadata passed: slug and display name present
✓ no raw internal fields: enforced by the copy-contract test over the rendered page
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