This page shows what was measured, who it was measured in, and what that does not settle.
What Phenylbutyric Acid does in the body
PHEBURANE is indicated as adjunctive therapy to standard of care, which includes dietary management, for the chronic management of adult and pediatric patients with urea cycle disorders (UCDs), involving deficiencies of carbamylphosphate synthetase (CPS), ornithine transcarbamylase (OTC) or argininosuccinic acid synthetase (AS).
From the FDA-approved label: Sodium phenylbutyrate is a pro-drug and is metabolized to phenylacetate. Phenylacetate is a metabolically-active compound that conjugates with glutamine via acetylation to form phenylacetylglutamine. Phenylacetylglutamine is excreted by the kidneys, hence providing an alternate vehicle for waste nitrogen excretion.
Why people take it. PHEBURANE is indicated as adjunctive therapy to standard of care, which includes dietary management, for the chronic management of adult and pediatric patients with urea cycle disorders (UCDs), involving deficiencies of carbamylphosphate synthetase (CPS), ornithine transcarbamylase (OTC) or argininosuccinic acid synthetase (AS).
What happened in people
RNAWiki has not yet published a reviewed conclusion for this use.
§ A fixed RNAWiki sentence
Where this came from
Wording RNAWiki always uses, not a finding about this substance.
No reviewed claim names a result for any goal on this record.
No source is stored against this line.
The limit that matters most
Not recorded.
Where it acts
Not recorded.
Kind of result
No result is published, so no kind of result applies yet
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 · NT6K61736T · read 2026-08-29
Its recorded molecular formula is C10H11NaO2, weighing 186.19.
US prescribing information · d15f2cbf-4d22-40b5-8ef9-16b9d323a7f9 · read 2026-08-30
Where each sentence above came from
The use the label states, quoted from it. No plain-language version of this sentence has been written.
The use the label states, quoted from it. It is written for a clinician, not for a reader without medical training.
No statement of the main limit is recorded.
The four opening statements run to 138 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.
Stand-in result
A stand-in result is a number measured because the real result takes too long.
A picture of it, and where the picture fails
It is like judging a journey by the speedometer rather than by arriving.
Where that stops being true. Speed does predict arrival. Many stand-in results do not predict the real one.
What people get wrong. A stand-in result is often reported as the result itself.
A surrogate endpoint substituted for a clinical endpoint, valid only where the substitution has been shown to hold.
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 11 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
Body weight
∅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.
∅Nothing in the sources checkedNo registered study lists a symptom measure for this goal.
△Only a number moved1 registered test measure.
∅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
Body weight
body composition
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.
△ Only a number moved
1 registered test measure.
— Not recorded
Harms were not a registered measure for this goal.
… Waiting for a reviewer
Who was studied is listed further down the page.
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.
What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.
The limits of this study, and where it came from
Main limit. No limitation is recorded for this study.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
openFDA Drugs@FDA · a recorded source, not a stored snapshot
openFDA NDC Directory · a recorded source, not a stored snapshot
openFDA SPL label · a recorded source, not a stored snapshot
PubChem PUG-REST · a recorded source, not a stored snapshot
Composite clinical TB score
✗ The study did not show it
Who was studied
NCT01698476
How many people
390
Study design
Phase 2
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated
What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.
The limits of this study, and where it came from
Main limit. No limitation is recorded for this study.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
openFDA Drugs@FDA · a recorded source, not a stored snapshot
openFDA NDC Directory · a recorded source, not a stored snapshot
openFDA SPL label · a recorded source, not a stored snapshot
PubChem PUG-REST · a recorded source, not a stored snapshot
To assess the Incidence of Treatment-Emergent Adverse Events during treatment with AMX0035
✗ The study did not show it
Who was studied
NCT05619783
How many people
352
Study design
Phase 3
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated
What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.
The limits of this study, and where it came from
Main limit. No limitation is recorded for this study.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
openFDA Drugs@FDA · a recorded source, not a stored snapshot
openFDA NDC Directory · a recorded source, not a stored snapshot
openFDA SPL label · a recorded source, not a stored snapshot
PubChem PUG-REST · a recorded source, not a stored snapshot
Part A: Change From Baseline to Week 24 in the Amyotrophic Lateral Sclerosis Functional Rating Scale Revised (ALSFRS-R) Total Score
✗ The study did not show it
Who was studied
NCT05237284
How many people
305
Study design
Phase 2
Compared against
Not recorded for this study
Kind of result
What a body can do day to day
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated
What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.
The limits of this study, and where it came from
Main limit. No limitation is recorded for this study.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
openFDA Drugs@FDA · a recorded source, not a stored snapshot
openFDA NDC Directory · a recorded source, not a stored snapshot
openFDA SPL label · a recorded source, not a stored snapshot
PubChem PUG-REST · a recorded source, not a stored snapshot
Proportion of pulmonary TB patients who are culture negative in sputum in week 4
✗ The study did not show it
Who was studied
NCT01580007
How many people
288
Study design
Phase 2
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated
What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.
The limits of this study, and where it came from
Main limit. No limitation is recorded for this study.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
openFDA Drugs@FDA · a recorded source, not a stored snapshot
openFDA NDC Directory · a recorded source, not a stored snapshot
openFDA SPL label · a recorded source, not a stored snapshot
PubChem PUG-REST · a recorded source, not a stored snapshot
HIV viral load
✗ The study did not show it
Who was studied
NCT01702974
How many people
279
Study design
Phase 2
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated
What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.
The limits of this study, and where it came from
Main limit. No limitation is recorded for this study.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
openFDA Drugs@FDA · a recorded source, not a stored snapshot
openFDA NDC Directory · a recorded source, not a stored snapshot
openFDA SPL label · a recorded source, not a stored snapshot
PubChem PUG-REST · a recorded source, not a stored snapshot
What we know
RNAWiki holds 6 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 healthEvidence recorded. Cholesterol, blood sugar, bone density. A stand-in, not the thing itself.5 registered measures of this kind.
■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 dishEvidence recorded. Cells or chemistry on a bench, far from a whole body.Stored mechanism abstracts describe steps measured in cells or tissue.
□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 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.
No registered study measured anything of this kind.
Measured
Things only a test, a scale or a device shows.
measures of liver function ast and alt
measures of liver function pt and ptt
measures of liver function coagulation factors
measures of liver function inr
body composition
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 (6)
safety and tolerability
dose limiting toxicities
rate of adverse events
treatment related adverse events as assessed by ctcae v5 0
systemic vascular resistance
treatment related adverse events
These are harms, study-process measures, or names the rules did not recognise. They are shown rather than dropped.
What it would be like to take◇Read from sources, not yet reviewed
How long anything takes
Nine different lengths of time that get confused with each other. None of them is worked out from another.
Before anything is noticed.RNAWiki does not store this separately, and never works it out from another figure on this page.
Before a test result moves.RNAWiki does not store this separately, and never works it out from another figure on this page.
Before performance moves.RNAWiki does not store this separately, and never works it out from another figure on this page.
How long the result was watched.No finished study window is recorded for a study that tested this substance.
How long people took it.How long people actually took it is not stored. The study window is not the same thing.
How long people were followed.Follow-up length is not stored separately. It is never read off the study window, which would be a different thing.
How fast the body clears it. 0.5 to 0.8 hour hours
Read from the label, which states: “Elimination The mean half-life of phenylbutyrate ranged from 0.5 to 0.8 hour.”
How long effects linger.RNAWiki does not store this separately, and never works it out from another figure on this page.
Beyond the studies. Nothing is recorded about the long term.
The longest finished study sets the edge of what anyone measured.
A study window is not how long people took it, and neither is how long they were followed. Where RNAWiki holds only one of the three, it shows one.
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.
BUPHENYL is indicated as adjunctive therapy in the chronic management of patients with urea cycle disorders involving deficiencies of carbamoyl phosphate synthetase (CPS), ornithine transcarbamylase (OTC), or argininosuccinic acid synthetase (AS). It is indicated in all patients with neonatal-onset deficiency (complete enzymatic deficiency, presenting within the first 28 days of life).
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.
What the label states about particular groups
On pediatric, the label states: “The safety and effectiveness of PHEBURANE have been established as adjunctive therapy to the standard of care, which includes dietary management, in the chronic management of pediatric patients with urea cycle disorders (UCDs), involving deficiencies of carbamylphosphate synthetase (CPS), ornithine transcarbamylase (OTC) or argininosuccinic acid synthetase (AS).”
US prescribing information · d15f2cbf-4d22-40b5-8ef9-16b9d323a7f9 · read 2026-08-30
On older people, the label states: “Clinical studies of PHEBURANE did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects.”
US prescribing information · d15f2cbf-4d22-40b5-8ef9-16b9d323a7f9 · read 2026-08-30
On people who are pregnant, the label states: “Risk Summary Available data with sodium phenylbutyrate use in pregnant women are insufficient to identify a drug associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes.”
US prescribing information · d15f2cbf-4d22-40b5-8ef9-16b9d323a7f9 · read 2026-08-30
On people who are breastfeeding, the label states: “Risk Summary There are no data on the presence of sodium phenylbutyrate and its metabolite in either human or animal milk, the effects on the breastfed infant, or the effects on milk production.”
US prescribing information · d15f2cbf-4d22-40b5-8ef9-16b9d323a7f9 · read 2026-08-30
On people with reduced liver function, the label states: “No studies with PHEBURANE were conducted in subjects with hepatic impairment.”
US prescribing information · d15f2cbf-4d22-40b5-8ef9-16b9d323a7f9 · read 2026-08-30
On people with reduced kidney function, the label states: “No studies with PHEBURANE were conducted in subjects with renal impairment.”
US prescribing information · d15f2cbf-4d22-40b5-8ef9-16b9d323a7f9 · read 2026-08-30
Where the result stopped carrying
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
Prescription only
❝ 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
✎ 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
Sold as tablet, powder, pellets, for suspension, given by the oral route.
✎ 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∅Nothing found in the sources checked
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.
∅Nothing found in the sources checked
No harm is recorded against this substance in the sources RNAWiki checked. Finding nothing is not the same as showing there is nothing.
The sources listed were searched and held nothing. That is not the same as nothing existing.
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◇Read from sources, not yet reviewed
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
✎ 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
Not recorded.
∅ Nothing recorded
Where this came from
RNAWiki holds nothing here and says so rather than guessing.
Nothing further is recorded about which forms are sold.
No source is stored against this line.
What is recorded as being sold
22 products list this as an active ingredient in the United States drug directory. 21 of them contain it and nothing else.
FDA National Drug Code directory · 66326-504 · read 2026-08-29
They are sold as pellet, powder and tablet, taken oral.
FDA National Drug Code directory · 66326-504 · read 2026-08-29
The regulator's established pharmacologic class for it is ammonium ion binding activity [moa] and nitrogen binding agent [epc].
FDA National Drug Code directory · 66326-504 · read 2026-08-29
7 published labels name it as an active ingredient. 7 of them describe this substance alone, which is where its own label text on this page comes from.
US prescribing information · 463a36fa-3eb2-4326-8bd0-c8c7a11bca3a · read 2026-08-29
Those labels are classed as human prescription drug.
US prescribing information · 463a36fa-3eb2-4326-8bd0-c8c7a11bca3a · read 2026-08-29
PHEBURANE is oral at 3 DOSAGE FORMS AND STRENGTHS Oral pellets: 84 g of sodium phenylbutyrate per PHEBURANE bottle as white to off-white coated pellets., recorded as fda label in effect 2026-07-17 in the United States.
US prescribing information · d15f2cbf-4d22-40b5-8ef9-16b9d323a7f9 · read 2026-08-30
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 Phenylbutyric Acid 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
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.
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 Phenylbutyric Acid 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.
Where else this substance is registered
FDA substance identifier (UNII)
NT6K61736T
RxNorm concept
199369
Checks this page had to pass
✓ Passed
Identity resolved
no open identity hold
✓ Passed
No unresolved merge across substance families
no quarantine open
✓ Passed
Every public sentence names a source
The opening statement carries the origin: Quoted from a stored source.
✗ Not passed
Trial roles classified for highlighted evidence
No registered study is classified as testing this substance.
✓ Passed
No internal keys in reader text
enforced by the copy-contract test over the rendered page
✗ Not passed
Safety mode resolved
No register row and no identity class settled the question.
✓ Passed
Canonical metadata present
slug and display name present
What is missing or unclear◇Read from sources, not yet reviewed
How this medicine reached us
Kept near the foot of the page. A historical event moves up only when it changes something about this substance today.
What the approval register records
11 approved applications cover products containing this substance. The earliest was NDA020573, approved 19960430 to HORIZON THERAP US.
This order is fixed in code and does not count clicks or time on the page.
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.
The path through the body — 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.
Claims that go past the evidence — 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.
Recorded evidence blocks (11)
Q1
What did Phenylbutyric Acid's largest trial (120 people) and its longest (6.8 years) measure?
120 people in Phenylbutyric Acid's largest registered study, 6.8 years in its longest registered window, measuring Toxicity of flurouracil (FU) when given in escalating doses in combination with fixed doses of phenlylbutyrate (PB), indomethacin and recombinant human interferon-gamma (rhIFNg) to patients with… ClinicalTrials.gov · 2026-09-01
18 phase2, 14 phase1, 3 na, 3 phase4, 2 phase3, 1 early phase1, 1 na or unstated; NCT00771901; 2014-12; no ageing endpoint recorded. Last human test completed 2024, NCT05028803.
Interpretation These counts include studies where Phenylbutyric Acid 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
phase2
18
phase1
14
na
3
phase4
3
phase3
2
early phase1
1
2 more recorded rows
na or unstated
1
Last recorded human testNCT05028803
2024-03-01
recorded 2026-09-01 · last checked 2026-09-04
Q2
From mouse to human: where has Phenylbutyric Acid shown mechanism-only?
Interpretation Toxicity of flurouracil (FU) when given in escalating doses in combination with fixed doses of phenlylbutyrate (PB), indomethacin and recombinant human… — the recorded outcome words.
Show the evidence
mouse
mechanism-only
humanNCT00002796
mechanism-only; Toxicity of flurouracil (FU) when given in escalating doses in combination with fixed doses of phenlylbutyrate (PB), indomethacin and recombinant human interferon-gamma (rhIFNg) to patients with advanced colorectal cancer (Phase I); 36
accrual/recruitment (1), sponsor decision unspecified (1) and other (4): Phenylbutyric Acid's stop wording, clustered. ClinicalTrials.gov · 2026-09-01
"Administratively complete."; 6 of 36 registered studies
Show the evidence
Trial
NCT00002796
terminated; "Administratively complete."
NCT00439218
terminated; "Extremely slow enrollment"
NCT00439569
terminated; "Due to poor compliance with study drug administration."
NCT01096095
withdrawn; "Regulatory authorities did not allow the entrance of the study drug in the country"
NCT05349435
terminated; "Sponsor has decided to discontinue development of fezegepras based on initial pharmacokinetic results"
NCT06069375
suspended; "Study has been temporarily stopped until another study is completed. Data from the other study may inform changes to this study."
recorded 2026-09-01 · last checked 2026-09-04
Q4
Phenylbutyric Acid's half-life is 0.5 to 0.8 hour hours — which schedules were studied?
0.5 to 0.8 hour hours, the half-life Phenylbutyric Acid's label states. openfda-label · d15f2cbf-4d22-40b5-8ef9-16b9d323a7f9 · 2026-08-30
Show the evidence
half life
0.5 to 0.8 hour hours; Elimination The mean half-life of phenylbutyrate ranged from 0.5 to 0.8 hour.
metabolism
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Sodium phenylbutyrate is a pro-drug and is metabolized to phenylacetate.
recorded 2026-08-30 · last checked 2026-09-04
Q5
Could one person measure Phenylbutyric Acid's effect on safety and tolerability?
Safety and tolerability: measured in Phenylbutyric Acid's trials.
Interpretation safety and tolerability is the recorded endpoint.
Show the evidence
biomarkers
safety and tolerability; 2026-09-01
measures of liver function ast and alt; 2026-09-01
measures of liver function pt and ptt; 2026-09-01
measures of liver function coagulation factors; 2026-09-01
measures of liver function inr; 2026-09-01
dose limiting toxicities; 2026-09-01
5 more recorded rows
biomarkers
body composition; 2026-09-01
biomarkers
rate of adverse events; 2026-09-01
biomarkers
treatment related adverse events as assessed by ctcae v5 0; 2026-09-01
biomarkers
systemic vascular resistance; 2026-09-01
biomarkers
treatment related adverse events; 2026-09-01
half life
2026-09-04; halfLife; hours; 0.5 to 0.8 hour; 2026-08-30
human trials at or under30
23
smallest human trial
0; NCT00387530; PHASE2; the smallest recorded human enrolment at or below 30; the registry states no direction of its result; WITHDRAWN
Q6
Which of body composition, dose limiting toxicities and measures of liver function ast and alt did Phenylbutyric Acid's trials measure?
body composition, dose limiting toxicities and measures of liver function ast and alt lead 11 outcome terms across Phenylbutyric Acid's trials. ClinicalTrials.gov · 2026-09-01
measures of liver function coagulation factors, measures of liver function inr, dose limiting toxicities, body composition, rate of adverse events and treatment related adverse events as assessed by ctcae v5 0 follow.
Show the evidence
safety and tolerability
1
measures of liver function ast and alt
1
measures of liver function pt and ptt
1
measures of liver function coagulation factors
1
measures of liver function inr
1
dose limiting toxicities
1
5 more recorded rows
body composition
1
rate of adverse events
1
treatment related adverse events as assessed by ctcae v5 0
1
systemic vascular resistance
1
treatment related adverse events
1
recorded 2026-09-01 · last checked 2026-09-04
Q7
Which of Phenylbutyric Acid's 3 ongoing trials reports first?
Systemic vascular resistance; Number of participants with treatment related adverse events as assessed by CTCAE v5.0; latest 2029-06-01
Show the evidence
Trial
NCT06645769
"Na-Phenylbutyrate VAscular Trial"; n 30; "Systemic vascular resistance"; 2029-06-01
NCT06773026
"Study of Sodium Phenylbutyrate (ACER-001) for the Treatment of Pediatric and Adults Patients With Medium Chain Acyl-CoA Dehydrogenase Deficiency (MCADD)"; n 24; "Number of participants with treatment related adverse events as assessed by CTCAE v5.0"; 2027-07
NCT07125066
"An Individual Patient, Open Label Study to Use ACER-001 to Treat Combined D,L-2 Hydroxyglutaric Aciduria (C-2HGA)"; n 1; "Number of treatment related adverse events"; 2027-12
recorded 2026-09-01 · last checked 2026-09-04
Q8
Which 13 trials of Phenylbutyric Acid posted no result?
Posted no result
13 of 13 completed trials
Registrations
NCT00001565, NCT00006240, NCT00006450, NCT00006019, NCT00006239 and NCT00005639, and 7 more
Completion dates
oldest 2000-10; newest 2024-03-01
Show the evidence
Trial
NCT00001565
2000-10
NCT00006240
2001-08
NCT00006450
2002-07
NCT00006019
2003-08
NCT00006239
2005-03
NCT00005639
2005-07
7 further recorded trials
NCT00977600
2005-07
NCT00212316
2006-06
NCT00107770
2007-09
NCT00533559
2010-03
NCT03734263
2020-12-30
NCT04421677
2022-01-20
NCT05028803
2024-03-01
Q9
At the median, Phenylbutyric Acid's trials enrolled 20 people — anything larger?
Median enrolment
20
Largest enrolment
120
Registered trials counted
31
Q10
Phenylbutyric Acid and BCRP, CYP2C19 and CYP2C8: shared by which compounds?
BCRP, CYP2C19 and CYP2C8 appear in Phenylbutyric Acid's recorded interaction sentences, 2 in all. openfda-label+europepmc · 2026-08-30
Interpretation pharmacokinetics
Show the evidence
CYP2C19pharmacokinetics
Drug Interaction Studies In Vitro Studies Sodium phenylbutyrate or phenylacetate is not an inhibitor of CYP2C8, CYP2C19 and CYP3A at clinically relevant concentrations.
CYP2C8pharmacokinetics
Drug Interaction Studies In Vitro Studies Sodium phenylbutyrate or phenylacetate is not an inhibitor of CYP2C8, CYP2C19 and CYP3A at clinically relevant concentrations.
recorded 2026-08-30 · last checked 2026-09-04
Q11
What is recorded about Phenylbutyric Acid and mTOR?
"The compound sodium phenylbutyrate (PB) has been shown to promote branched-chain amino acid (BCAA) catabolism, and as such has been proposed as a treatment for disorders with enhanced BCAA levels: does PB induce muscle protein catabolism by forcing BCAA degradation away from muscle protein synthesis and mechanistic target of rapamycin…" — where Phenylbutyric Acid and mTOR appear together. Europe PMC · pathway abstract search · 2021-01-20
"The compound sodium phenylbutyrate (PB) has been shown to promote branched-chain amino acid (BCAA) catabolism, and as such has been proposed as a treatment for disorders with enhanced BCAA levels: does PB induce muscle protein catabolism by forcing BCAA degradation away from muscle protein synthesis and mechanistic target of rapamycin (mTOR) inhibition?"
autophagyPMID 28618969
"Inhibiting endoplasmic reticulum stress by pretreatment with pharmacological inhibitors such as sodium phenylbutyrate and mithramycin or by silencing CHOP using CHOP small interfering RNA, blocked penfluridol-induced autophagy."
IGF-1PMID 16832072
"Remaining agents (AEOL 10150, arimoclomol, celastrol, coenzyme Q10, copaxone, IGF-1-viral delivery, memantine, NAALADase inhibitors, nimesulide, scriptaid, sodium phenylbutyrate, thalidomide, trehalose) require additional preclinical animal data, human toxicity and pharmacokinetic data including CNS penetration prior to proceeding to large scale phase III human testing."
recorded 2021-01-20 · last checked 2026-09-04
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 · mixed register set; per-register licences in docs/specs/corpus-20k-sources.md · openFDA / DailyMed — US Government work
✗ 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: 8 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
This is a record of evidence. It is not medical advice, and it does not say this substance suits you. Nothing here says any substance on RNAWiki is appropriate for a child.