No plain explanation of what this changes is stored.
No recorded use is stored in reader language.
No statement of the main limit is recorded.
The four opening statements run to 26 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.
Changes in mean hemoglobin concentrations
✗ The study did not show it
Who was studied
NCT02567981
How many people
4577
Study design
Not applicable
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.
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
openFDA NDC Directory · a recorded source, not a stored snapshot
openFDA Drugs@FDA · a recorded source, not a stored snapshot
Europe PMC · a recorded source, not a stored snapshot
ClinicalTrials.gov · a recorded source, not a stored snapshot
Composite outcome
✗ The study did not show it
Who was studied
NCT05060731
How many people
570
Study design
Phase 4
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.
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
openFDA NDC Directory · a recorded source, not a stored snapshot
openFDA Drugs@FDA · a recorded source, not a stored snapshot
Europe PMC · a recorded source, not a stored snapshot
ClinicalTrials.gov · a recorded source, not a stored snapshot
Proportion of patients who achieve normalized Hb-levels or increased Hb of at least 1.5 g/dl
✗ The study did not show it
Who was studied
NCT03817957
How many people
187
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.
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
openFDA NDC Directory · a recorded source, not a stored snapshot
openFDA Drugs@FDA · a recorded source, not a stored snapshot
Europe PMC · a recorded source, not a stored snapshot
ClinicalTrials.gov · a recorded source, not a stored snapshot
Lipid peroxidation Malondialdehyde (MDA)
✗ The study did not show it
Who was studied
NCT03740295
How many people
60
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.
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
openFDA NDC Directory · a recorded source, not a stored snapshot
openFDA Drugs@FDA · a recorded source, not a stored snapshot
Europe PMC · a recorded source, not a stored snapshot
ClinicalTrials.gov · a recorded source, not a stored snapshot
fractional iron absorption
✗ The study did not show it
Who was studied
NCT03762148
How many people
46
Study design
Not applicable
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.
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
openFDA NDC Directory · a recorded source, not a stored snapshot
openFDA Drugs@FDA · a recorded source, not a stored snapshot
Europe PMC · a recorded source, not a stored snapshot
ClinicalTrials.gov · a recorded source, not a stored snapshot
Determination of iron absorption from FAP and from ferric pyrophosphate relative to Ferrous sulfate
✗ The study did not show it
Who was studied
NCT05642689
How many people
40
Study design
Not applicable
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.
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
openFDA NDC Directory · a recorded source, not a stored snapshot
openFDA Drugs@FDA · a recorded source, not a stored snapshot
Europe PMC · a recorded source, not a stored snapshot
ClinicalTrials.gov · 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 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
No description of who was studied is recorded.
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
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 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 (11)
It was studied for a different goal
The studies measured something else entirely. Nothing in this record points to this reason.
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
Varies by country
❝ 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
Not recorded.
∅ Nothing recorded
Where this came from
RNAWiki holds nothing here and says so rather than guessing.
No form or route is recorded.
No source is stored against this line.
Who oversees it
Not usually supervised: sold as a supplement or food ingredient where recorded. That is a legal category, not a safety judgement.
❝ Quoted from a source
Where this came from
Copied from a source RNAWiki stored, with the source named.
The identity record classes it as a supplement ingredient; no medicines register records an approval.
No source is stored against this line.
What is in the pack
Not recorded.
∅ Nothing recorded
Where this came from
RNAWiki holds nothing here and says so rather than guessing.
Nothing is recorded about product quality.
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
Not recorded.
∅ Nothing recorded
Where this came from
RNAWiki holds nothing here and says so rather than guessing.
The exact form studied is not recorded.
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
66 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 · 597caf33-5107-9dec-e063-6294a90a5fcd · read 2026-08-29
Those labels are classed as human otc drug and human prescription drug.
US prescribing information · 597caf33-5107-9dec-e063-6294a90a5fcd · read 2026-08-29
4270 marketed supplement labels list this ingredient, classed as mineral.
Those labels carry all other, nutrient and structure/function claims. A claim of that kind is written by the manufacturer and is not assessed by any regulator, so its presence says nothing about whether it is true.
This order is fixed in code and does not count clicks or time on the page.
What is not here
10 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.
How close this is to real life — found nothing in the sources checked.
The path through the body — 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.
Claims that go past the evidence — 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.
Recorded evidence blocks (6)
Q1
On the Ferrous Phosphate label: indicated for what?
"Helps temporarily relieve: occasional poor appetite; feelings of tiredness or weakness; congestion; aches; elevated body temperature; and headaches.": indications and usage on Ferrous Phosphate's label. DailyMed label · 53ba97b3-db1d-6d8a-e063-6394a90aa8f1 · 2026-06-08
Q2
175 registered trials of Ferrous Phosphate — at which phases?
Registered studies posting no result
136 of 175
175 registered studies of Ferrous Phosphate: 64 na, 42 phase3, 42 phase4, 18 phase2, 5 early phase1, 5 phase1, 3 na or unstated. CLINICALTRIALS_SNAPSHOT · 2026-09-01
0 with a PubMed record
Show the evidence
na
64
phase3
42
phase4
42
phase2
18
early phase1
5
phase1
5
7 more recorded rows
na or unstated
3
completed
114
unknown
20
recruiting
13
terminated
13
not yet recruiting
8
withdrawn
7
recorded 2026-09-01 · last checked 2026-09-04
Q3
20 of Ferrous Phosphate's trials stopped: safety, accrual/recruitment, funding/business, other?
safety (2), accrual/recruitment (8), funding/business (4) and other (6): Ferrous Phosphate's stop wording, clustered. CLINICALTRIALS_SNAPSHOT · 2026-09-01
"The study was terminated because of significant enrollment challenges"; 20 of 175 registered studies
Show the evidence
Trial
NCT00223938
terminated; "The study was terminated because of significant enrollment challenges"
NCT00830037
terminated; "Terminated by the DSMB based on low chance of finding differences in mGFR slopes, but higher risk of serious adverse events in the IV iron group (aIRR = 1.60)"
NCT00929409
terminated; "Stopped prematurely because too few patients were recruited."
NCT00999479
withdrawn; "Poor enrollment"
NCT01155375
terminated; "Several factors contributed to significant challenges in enrollment and led the Sponsor to discontinue the AMAG-FER-CKD-251 study as designed."
NCT01155388
terminated; "Several factors contributed to significant challenges in enrollment and led the Sponsor to discontinue the AMAG-FER-CKD-252 study as designed."
14 further recorded trials
NCT01438372
withdrawn; "The study was terminated prior to enrolling patients as we were unable to secure enough funding to complete the study."
NCT01656434
terminated; "Business reasons"
NCT01837030
withdrawn; "not feasible due to funding"
NCT01865175
withdrawn; "Institution required IND, although FDA did not, so institution did not allow enrollment"
NCT01908543
terminated; "Technical issues with availability of relevant personnel"
NCT01975272
terminated; "Disapointing randomization rate"
NCT02825719
terminated; "Ulipristal was withdrawal from the market"
NCT02839096
terminated; "Lack of funds, PI left University"
NCT03777514
withdrawn; "Study wasn't started."
NCT04087993
withdrawn; "difficult recruitment - redesign in discussion"
NCT04594070
terminated; "Unable to recruit enough participants"
NCT04610827
terminated; "Change in personnel and lack of resources to continue."
NCT05152641
withdrawn; "The program priority for execution of this clinical trial changed prior to enrollment of the first patient. The study was not withdrawn due to any safety concerns."
ClinicalTrials.gov — US Government work · mixed register set; per-register licences in docs/specs/corpus-20k-sources.md · openFDA / DailyMed — US Government work
✗ required summary fields resolved: 3 required field(s) not terminal: Best-supported result, Biggest unanswered question, Human evidence
✓ public claims reviewed: 0 reviewed claim(s); drafts are never rendered
✓ source coverage passed: 4 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.