This page shows what was measured, who it was measured in, and what that does not settle.
What Sodium iodide (131i) does in the body
HICON ® is indicated for the treatment of hyperthyroidism and selected cases of thyroid carcinoma.
From the FDA-approved label: Iodide is actively transported by the sodium-iodide symporter (NIS) protein, in thyroid follicular cells. Iodide is concentrated in follicular cells to levels up to 50 times higher than in the plasma. Iodide is metabolically oxidized by thyroid peroxidase to iodinium (I + ) which in turn iodinates tyrosine residues of thyroglobulin (tri or tetra-iodinated tyrosine). The beta emission of I 131 is responsible for the therapeutic effect.
Why people take it. HICON ® is indicated for the treatment of hyperthyroidism and selected cases of thyroid carcinoma.
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
Professional supervision is normally required. A regulator classifies this substance in a way that restricts how it is supplied.
What the registries record it as
The substance registry classes this as chemical.
FDA substance registry · 29VCO8ACHH · read 2026-08-29
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 108 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.
Formulation
A formulation is the exact made-up form a substance comes in.
A picture of it, and where the picture fails
It is like the difference between a whole bean and instant coffee.
Where that stops being true. Coffee tastes different. A formulation can change how much reaches the blood.
What people get wrong. Two products with the same name are assumed to behave the same. They often do not.
The specific composition and physical form of a product, including salt, excipients and release profile.
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.
Phase II: monthly patient accrual rates
✗ The study did not show it
Who was studied
NCT01398085
How many people
504
Study design
Phase 2/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
blood volume deviation (%) from individual predicted volumes
✗ The study did not show it
Who was studied
NCT01783288
How many people
110
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. 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
Natriuretic effect of empagliflozin or placebo as an adjuvant to loop diuretic therapy
✗ The study did not show it
Who was studied
NCT05553938
How many people
60
Study design
Phase 1
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
Number of Participants (Par.) During Initial Treatment Exposed to the Indicated Dose Levels of the Therapeutic Dose (TD), Re-dose, and Total Dose (TD + Re-dose)
✗ The study did not show it
Who was studied
NCT01536561
How many people
59
Study design
Phase 1
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
Change in Blood Volume
✗ The study did not show it
Who was studied
NCT03446651
How many people
50
Study design
Early phase 1
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
Diagnostic accuracy of F-18-TFB PET/CT
✗ The study did not show it
Who was studied
NCT07436455
How many people
50
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. 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 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.
Sodium Iodide I 131 Capsules Diagnostic is indicated for use in adults for: Assessment of thyroid function using radioactive iodine (RAI) uptake test Imaging the thyroid (scintigraphy) Sodium Iodide I 131 Capsules Diagnostic is a radioactive diagnostic agent indicated for the assessment of thyroid function and for thyroid imaging.
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 HICON ® have not been established in pediatric patients.”
US prescribing information · 524a0dac-6e2b-2c0c-04b4-76d85dba63c5 · read 2026-08-30
On older people, the label states: “Clinical experience has not identified differences in safety or effectiveness in geriatric patients compared to younger patients.”
US prescribing information · 524a0dac-6e2b-2c0c-04b4-76d85dba63c5 · read 2026-08-30
On people who are pregnant, the label states: “Risk Summary HICON ® is contraindicated in pregnancy because fetal exposure can lead to neonatal hypothyroidism, which in some cases is severe and irreversible [See Warnings and Precautions ( 5.4 )] .”
US prescribing information · 524a0dac-6e2b-2c0c-04b4-76d85dba63c5 · read 2026-08-30
On people who are breastfeeding, the label states: “Risk Summary HICON ® is contraindicated during lactation because I 131 concentrates in the breast during lactation via the increased expression of the sodium iodide symporter in breast tissue and can lead to hypothyroidism in the infant through breastfeeding.”
US prescribing information · 524a0dac-6e2b-2c0c-04b4-76d85dba63c5 · read 2026-08-30
On people with reduced kidney function, the label states: “HICON ® is primarily excreted by the kidneys.”
US prescribing information · 524a0dac-6e2b-2c0c-04b4-76d85dba63c5 · 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 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.
A different form was studied
The studied form is not the form on the shelf.
On this record: This record is linked to 1 related forms. Evidence does not carry across all of them.
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)
It was studied for a different goal
The studies measured something else entirely. 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
Professional supervision is normally required. A regulator classifies this substance in a way that restricts how it is supplied.
❝ Quoted from a source
Where this came from
Copied from a source RNAWiki stored, with the source named.
Suppression classes recorded: S1, S3.
No source is stored against this line.
What is in the pack
Sold as solution, capsule, 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
4 products list this as an active ingredient in the United States drug directory. 4 of them contain it and nothing else.
FDA National Drug Code directory · 72063-101 · read 2026-08-29
They are sold as capsule, solution and solution, concentrate, taken oral.
FDA National Drug Code directory · 72063-101 · read 2026-08-29
The regulator's established pharmacologic class for it is radioactive therapeutic agent [epc] and radiopharmaceutical activity [moa].
FDA National Drug Code directory · 72063-101 · read 2026-08-29
3 published labels name it as an active ingredient. 3 of them describe this substance alone, which is where its own label text on this page comes from.
US prescribing information · 524a0dac-6e2b-2c0c-04b4-76d85dba63c5 · read 2026-08-29
Those labels are classed as human prescription drug.
US prescribing information · 524a0dac-6e2b-2c0c-04b4-76d85dba63c5 · read 2026-08-29
HICON is oral at 3 DOSAGE FORMS AND STRENGTHS HICON ® is available in 1 mL size, clear vials containing a colorless, aqueous, concentrated Sodium Iodide I 131 Solution USP [9,250 MBq (250 mCi), 18,500 MBq (500 mCi), and 37,000 MBq (1,00…, recorded as fda label in effect 2025-01-21 in the United States.
US prescribing information · 524a0dac-6e2b-2c0c-04b4-76d85dba63c5 · 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.
This order is fixed in code and does not count clicks or time on the page.
What is not here
9 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.
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 (8)
Q2
On the Sodium iodide (131i) label: indicated for what?
"HICON ® is indicated for the treatment of hyperthyroidism and selected cases of thyroid carcinoma. HICON ® is a radioactive therapeutic agent indicated for the treatment of hyperthyroidism and selected cases of carcinoma of the thyroid.": indications and usage on Sodium iodide (131i)'s label. DailyMed label · 524a0dac-6e2b-2c0c-04b4-76d85dba63c5 · 2026-08-30
Q3
42 registered trials of Sodium iodide (131i) — at which phases?
Registered studies posting no result
31 of 42
42 registered studies of Sodium iodide (131i): 14 na, 10 phase2, 6 phase3, 6 phase4, 4 na or unstated, 3 phase1. CLINICALTRIALS_SNAPSHOT · 2026-09-01
1 with a PubMed record
Show the evidence
na
14
phase2
10
phase3
6
phase4
6
na or unstated
4
phase1
3
7 more recorded rows
completed
23
terminated
6
unknown
6
active not recruiting
4
no longer available
1
not yet recruiting
1
recruiting
1
recorded 2026-09-01 · last checked 2026-09-04
Q4
5 of Sodium iodide (131i)'s trials stopped: safety, accrual/recruitment?
terminated; "The institutional review board recommended the study stop enrollment prior to achieving its initial sample size for patient safety."
recorded 2026-09-01 · last checked 2026-09-04
Q5
Human studies of Sodium iodide (131i) used 240 mg Iodine — over how long?
studies of Sodium iodide (131i) used the recorded amount. ClinicalTrials.gov · 2026-09-01
3 recorded entries; human; also "240 mg Iodine", "240 mg Iodine/ml IDR 2.0 gI/s", "Iodide (150 μg/day)"
Show the evidence
human
NCT02462044
240 mg Iodine
NCT02462044
240 mg Iodine/ml IDR 2.0 gI/s
NCT05382793
Iodide (150 μg/day)
recorded 2026-09-01 · last checked 2026-09-04
Q6
Which running trial of Sodium iodide (131i) could settle lifespan?
NCT04743661 measures 2-year event free survival (EFS) in the Recurrent Medulloblastoma Cohort, reading out 2027-09-30.
1 open trial; n 62; "131I-Omburtamab, in Recurrent Medulloblastoma and Ependymoma"
Show the evidence
TrialNCT04743661
"131I-Omburtamab, in Recurrent Medulloblastoma and Ependymoma"; n 62; "2-year event free survival (EFS) in the Recurrent Medulloblastoma Cohort"; 2027-09-30
Q7
Which 14 trials of Sodium iodide (131i) posted no result?
Posted no result
14 of 14 completed trials
Registrations
NCT00277589, NCT01717729, NCT03889431, NCT01985204, NCT02927119 and NCT00638092, and 8 more
Completion dates
oldest 2008-12; newest 2023-12-15
Show the evidence
Trial
NCT00277589
2008-12
NCT01717729
2012-10
NCT03889431
2013-08-10
NCT01985204
2014-07
NCT02927119
2014-12
NCT00638092
2015-05
8 further recorded trials
NCT02462044
2015-09
NCT01413113
2015-10
NCT02771704
2016-02
NCT00791466
2016-05
NCT02359279
2016-06
NCT02018094
2017-01-02
NCT03431701
2019-06-30
NCT05382793
2023-12-15
Q8
At the median, Sodium iodide (131i)'s trials enrolled 67 people — anything larger?
Median enrolment
67
Largest enrolment
1337
Registered trials counted
41
Q9
What do 589 spontaneous reports say about Sodium iodide (131i) — and not say?
These are reports people sent to a regulator. They do not show the medicine caused the reaction. Nobody counted how many people took the medicine and reported nothing. The same event can be reported more than once, and many reports are incomplete. News coverage, lawsuits and new warnings change how often people report. A count is not a rate and not a risk.
Sodium iodide (131i) appears in spontaneous reports to regulators. Across the 10 most-reported reaction terms, 589 reaction mentions were counted: hypothyroidism 382; endocrine ophthalmopathy 33; treatment failure 26; acute myeloid leukaemia 24. FAERS via Open Targets · CHEMBL1201084 · 2026-06-24
Show the evidence
hypothyroidism
382
endocrine ophthalmopathy
33
treatment failure
26
acute myeloid leukaemia
24
dacryostenosis acquired
24
hyperthyroidism
21
4 more recorded rows
parathyroid tumour benign
21
abortion spontaneous
20
basedow's disease
19
hyperparathyroidism
19
recorded 2026-06-24 · last checked 2026-09-04
Where it is registeredIdentifiers, relations and other names
ChEMBL 37 — CC BY-SA 3.0 Unported · ChEMBL ATC CC BY-SA · ClinicalTrials.gov — US Government work · Open Targets 26.06 — CC0 · 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: 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
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.