This page shows what was measured, who it was measured in, and what that does not settle.
What Zinc does in the body
Swallowed daily at high doses, the same element blocks copper absorption, and copper deficiency is not a subtle condition.
Zinc is a structural component of thousands of proteins, so a genuine shortage disables enzymes and immune cells across the body. What a lozenge does is different and local: it releases free zinc ions into the throat, where they appear to interfere with the rhinovirus replication cycle and with the receptor the virus uses to enter cells. That only happens if the lozenge actually releases free ionic zinc, which depends on what the zinc is bound to and how much of it there is.
Why people take it. Taken at the first sign of a cold, and daily for immune support
What happened in people
Zinc lozenges above 75 mg per day shortened colds; zinc acetate pooled to a 42% duration reduction and other salts to 20%
✎ 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.
Jafek BW, Linschoten MR, Murrow BW. Anosmia after intranasal zinc gluconate use. Am J Rhinol 2004;18:137-141 (15283486) · a recorded source, not a stored snapshot
The best-evidenced use of oral zinc anywhere is childhood diarrhoea in populations where deficiency is common — a repletion effect, not an antiviral one
Where it acts
Oropharyngeal mucosa for the lozenge effect; duodenal and jejunal enterocyte for absorption and for the copper interaction
Kind of result
The kind of result is not recorded
Supervision
Not usually supervised: sold as a supplement or food ingredient where recorded. That is a legal category, not a safety judgement.
What the registries record it as
The supplement label database classes it as mineral, under the name Zinc.
A person wrote this explanation into the record, with the studies named in the path below.
The recorded use, written for a reader without medical training. Not signed off.
A limit recorded against this substance. Not signed off as a reviewed claim.
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.
Randomisation
Randomisation means chance decides who gets which treatment.
A picture of it, and where the picture fails
It is like a coin toss deciding the groups.
Where that stops being true. A coin toss is fair once. Fairness here comes from doing it for everyone.
What people get wrong. It is thought to make groups identical. It makes them similar on average, including on things nobody measured.
Allocation of participants to arms by a chance process, so that unmeasured factors are balanced in expectation.
Confidence interval
A confidence interval is the range the true answer is likely to sit in.
A picture of it, and where the picture fails
It is like a weather forecast giving a range rather than one number.
Where that stops being true. A forecast range covers tomorrow. This one covers what the study could resolve.
What people get wrong. The middle number is read as the answer. A range crossing zero means no change is still possible.
An interval estimate that would contain the true parameter in a stated proportion of repeated studies.
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 40 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
Focus
∅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.
∅Nothing in the sources checkedNo registered study lists a test result for this goal.
∅Nothing in the sources checkedNo registered study lists a body-step measure for this goal.
—Not recordedHarms were not a registered measure for this goal.
—Not recordedNo finished study window is recorded.
…Waiting for a reviewerWho was studied is listed further down the page.
Blood sugar
∅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
Focus
cognitive development
Blood sugar
acute insulin response from ivgtt
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.
— Not recorded
Harms were not a registered measure for this goal.
… Waiting for a reviewer
Who was studied is listed further down the page.
△ Only a number moved
1 registered test measure.
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.
Proportion developing a cold (prevention) and mean duration of cold in days (treatment)
✓ The study showed what it set out to show
Who was studied
Cochrane CD014914 — zinc for prevention and treatment of the common cold
How many people
8526
Study design
Cochrane systematic review of 34 randomised trials
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Treatment duration MD -2.37 days (95% CI -4.21 to -0.53), I2 = 97%, low certainty; prevention RR 0.93 (95% CI 0.85 to 1.01), low certainty
Repeated elsewhere
Partially Replicated
What this does not prove. Meeting one endpoint in one population does not carry to other goals or other people.
The limits of this study, and where it came from
Main limit. Non-serious adverse events probably increased with treatment zinc, RR 1.34 (95% CI 1.15 to 1.55), moderate certainty — a higher certainty grade than any efficacy finding in the review. No treatment study reported serious adverse events at all.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral lozenge, tablet, capsule or syrup; formerly also an intranasal gel
Interval reported. 95% CI -4
Written into the record, not signed off as a reviewed claim.
Jafek BW, Linschoten MR, Murrow BW. Anosmia after intranasal zinc gluconate use. Am J Rhinol 2004;18:137-141 (15283486) · a recorded source, not a stored snapshot
Percentage reduction in common cold duration by total daily zinc dose
✓ The study showed what it set out to show
Who was studied
Hemila 2011 dose-stratified pooling of 13 zinc lozenge comparisons
How many people
13
Study design
Systematic review with dose stratification
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Zinc acetate above 75 mg/day: 42% reduction (95% CI 35% to 48%); other salts above 75 mg/day: 20% (95% CI 12% to 28%); below 75 mg/day: uniformly no effect
Repeated elsewhere
Replicated
What this does not prove. Meeting one endpoint in one population does not carry to other goals or other people.
The limits of this study, and where it came from
Main limit. Sample size here counts trial comparisons, not participants. High-dose zinc lozenges taste unpleasant, which makes blinding hard, and the review could not exclude unblinding as a contributor.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral lozenge, tablet, capsule or syrup; formerly also an intranasal gel
Interval reported. 95% CI 35% to 48%); other salts above 75 mg/day: 20% (95% CI 12% to 28%); below 75 mg/day: uniformly no effect
Written into the record, not signed off as a reviewed claim.
Jafek BW, Linschoten MR, Murrow BW. Anosmia after intranasal zinc gluconate use. Am J Rhinol 2004;18:137-141 (15283486) · a recorded source, not a stored snapshot
Days to a 50% reduction in composite symptom severity score
✗ The study did not show it
Who was studied
NCT04342728 — COVID A to Z, zinc and ascorbic acid in ambulatory COVID-19
How many people
214
Study design
Randomised open-label factorial
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Overall P = .45 across the four arms
Repeated elsewhere
Failed to Replicate
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. Stopped early for low conditional power for benefit. Open-label with a subjective primary endpoint, so it was biased toward finding an effect and still found none.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral lozenge, tablet, capsule or syrup; formerly also an intranasal gel
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
Jafek BW, Linschoten MR, Murrow BW. Anosmia after intranasal zinc gluconate use. Am J Rhinol 2004;18:137-141 (15283486) · a recorded source, not a stored snapshot
Photographic progression to advanced AMD and at least 15-letter visual acuity loss
✓ The study showed what it set out to show
Who was studied
AREDS Report No. 8 — antioxidants and zinc for age-related macular degeneration
How many people
3640
Study design
Randomised double-masked placebo-controlled
Compared against
A dummy treatment
Kind of result
A number that stands in for health
What was found
Antioxidants plus zinc OR 0.72 (99% CI 0.52 to 0.98); zinc alone OR 0.75 (99% CI 0.55 to 1.03), not significant at the prespecified .01 level
Repeated elsewhere
Partially Replicated
What this does not prove. Meeting one endpoint in one population does not carry to other goals or other people.
The limits of this study, and where it came from
Main limit. Benefit was confined to participants already at high risk; the 1,063 lowest-risk participants had only a 1.3% five-year progression probability. The formulation included 2 mg copper to offset zinc-induced copper deficiency, and the beta carotene component was later removed after lung cancer signals in smokers.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral lozenge, tablet, capsule or syrup; formerly also an intranasal gel
Interval reported. Not recorded in this summary
Written into the record, not signed off as a reviewed claim.
Jafek BW, Linschoten MR, Murrow BW. Anosmia after intranasal zinc gluconate use. Am J Rhinol 2004;18:137-141 (15283486) · a recorded source, not a stored snapshot
Cochrane CD005436 — oral zinc for acute diarrhoea in children
How many people
10841
Study design
Cochrane systematic review of 33 randomised trials
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Over six months: MD -11.46 hours (95% CI -19.72 to -3.19), low certainty; malnourished children MD -26.39 hours (95% CI -36.54 to -16.23), high certainty
Repeated elsewhere
Replicated
What this does not prove. Meeting one endpoint in one population does not carry to other goals or other people.
The limits of this study, and where it came from
Main limit. No effect in children under six months. Not enough evidence to say whether zinc reduces death or hospitalisation. Trials were concentrated in populations at high baseline risk of zinc deficiency.
How far it carries. This study is recorded from the curated record, not from the registry match.
Form and route. Oral lozenge, tablet, capsule or syrup; formerly also an intranasal gel
Interval reported. 95% CI -19
Written into the record, not signed off as a reviewed claim.
Jafek BW, Linschoten MR, Murrow BW. Anosmia after intranasal zinc gluconate use. Am J Rhinol 2004;18:137-141 (15283486) · a recorded source, not a stored snapshot
RNAWiki holds 5 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.2 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 Yeast, C. elegans (roundworm), Drosophila (fruit fly), Mouse, Rat. 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 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
Zinc
What a person takes: Oral lozenge, tablet, capsule or syrup; formerly also an intranasal gel.
The measurement behind this step
Sold in the United States as a dietary supplement under DSHEA, so no agency reviewed efficacy or safety before sale. The lozenge and the swallowed capsule are pharmacologically different interventions: the lozenge acts locally in the oropharynx through free ionic zinc, the capsule acts systemically after ZIP4-mediated absorption, and evidence for one does not transfer to the other. The intranasal route is a third thing again and caused permanent injury. Elemental zinc is a minority of every salt by mass — 36% of zinc acetate, 14% of zinc gluconate — so label doses are not comparable unless the elemental figure is given.
Getting in
The lozenge only matters if it lets the zinc ion go
A zinc lozenge is not a dose of zinc — it is a dose of whatever free zinc it releases in your mouth. Many common sweeteners and acids grab the zinc and never let go, and a lozenge like that does nothing.
╌╌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
The proposed antiviral species is free Zn2+ released in the oropharynx. Citric acid, tartaric acid, sorbitol and mannitol chelate zinc and suppress ionic release. Hemila's dose stratification is the observable consequence: below 75 mg per day, five trials found nothing at all, while zinc acetate above 75 mg pooled to a 42% duration reduction.
Jafek BW, Linschoten MR, Murrow BW. Anosmia after intranasal zinc gluconate use. Am J Rhinol 2004;18:137-141 (15283486) · a recorded source, not a stored snapshot
Free zinc meets the airway epithelium the virus is replicating in
Rhinovirus enters cells lining the nose and throat through a specific docking protein. Zinc ions in that space appear to interfere both with the docking and with the virus assembling copies of itself.
╌╌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
Rhinovirus major-group serotypes enter through ICAM-1. Proposed zinc actions include interference with the viral 3C protease cleavage of the polyprotein and with capsid assembly, plus upregulation of interferon responses. None of these has been demonstrated in vivo at achievable mucosal free-zinc concentrations, which is why the Cochrane certainty grade for the duration effect is low despite the effect being real in the pooled estimate.
Jafek BW, Linschoten MR, Murrow BW. Anosmia after intranasal zinc gluconate use. Am J Rhinol 2004;18:137-141 (15283486) · a recorded source, not a stored snapshot
Swallowed zinc takes a different path entirely, through ZIP4
Zinc that goes down rather than staying in the throat is absorbed in the small intestine by a dedicated importer, the same one that is broken in a rare inherited disease of zinc deficiency.
╌╌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
ZIP4 (SLC39A4) on the apical enterocyte membrane carries most dietary zinc uptake and is upregulated during deficiency. Loss-of-function mutations cause acrodermatitis enteropathica, the disease that established zinc as essential. Luminal phytate chelates zinc and blocks this step, which is the mechanistic basis of zinc deficiency in high-phytate diets.
Jafek BW, Linschoten MR, Murrow BW. Anosmia after intranasal zinc gluconate use. Am J Rhinol 2004;18:137-141 (15283486) · a recorded source, not a stored snapshot
Zinc induces the protein that traps copper, and copper never gets in
Inside gut cells zinc switches on a small binding protein. That protein prefers copper. Copper gets stuck to it, the cell is shed into the gut a few days later, and the copper leaves with it.
╌╌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
Metallothionein induction by zinc is dose-dependent, and metallothionein binds Cu(I) with higher affinity than Zn(II). Copper is sequestered in the enterocyte and lost on cell turnover. This is the licensed pharmacology of zinc acetate in Wilson disease under NDA 020458, and it is the same event that produces sideroblastic anaemia, neutropenia and myelopathy in people who do not have Wilson disease.
Jafek BW, Linschoten MR, Murrow BW. Anosmia after intranasal zinc gluconate use. Am J Rhinol 2004;18:137-141 (15283486) · a recorded source, not a stored snapshot
Two outcomes from one element, separated only by dose and duration
Short bursts at cold onset may take a day or two off a cold. Sustained high daily intake quietly strips copper, and the first sign of that is often a blood count or a change in the way someone walks.
╌╌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
The therapeutic window is defined by time, not just amount. Cochrane found treatment courses of 4.5 to 21 days, over which copper depletion does not develop. Willis's three cases and Kumar's myelopathy series arose from sustained intake. Anaemia and neutropenia reverse completely on copper replacement; the neurological deficit generally does not.
Jafek BW, Linschoten MR, Murrow BW. Anosmia after intranasal zinc gluconate use. Am J Rhinol 2004;18:137-141 (15283486) · a recorded source, not a stored snapshot
No suggested links are held for this record, so nothing is hidden from this path.
What we know
The record describes 5 steps from taking it to an effect in a person.
How we know it
Each step names the study behind it in the technical detail beside it.
What this does not prove
A change inside the body is a reason to look. It is not a result in a person.
Why it matters
A reader can see exactly where the chain stops being measured in people.
What we still do not know
No reviewed claim binds any of these steps to a named population.
What it would be like to take◇Read from sources, not yet reviewed
Felt, measured, or meaningful
Three different things that get called the same word. Registered studies measured all three, and mixing them is how a blood test becomes a health claim.
Felt
Things a person could notice without a test.
No registered study measured anything of this kind.
Measured
Things only a test, a scale or a device shows.
lumbar spine bone mineral density by dxa
acute insulin response from ivgtt
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 (38)
progression of age related macular degeneration
progression of lens opacity
infant maize/zn supplementation trial
linear growth velocity
zn homeostasis studies
m at 1 5 months
duration of illness
treatment failure
risk of treatment failure
adverse effects
immune failure
duration of severe symptoms
adverse events and serious adverse events
reduction in duration of diarrhoea
reeudction in total stool volume
incidence of acute lower respiratory infection
growth
time to cessation of severe pneumonia
illnesses requiring visits to healthcare providers
stool output
These are harms, study-process measures, or names the rules did not recognise. They are shown rather than dropped.
What is missing or unclear◇Read from sources, not yet reviewed
Were people like you studied?
RNAWiki cannot tell whether a study fits you. It can show who was in it, and where the result stops carrying.
Who was studied
People similar to this profile were included.
Adults taking lozenges at cold onset, people on daily multivitamins containing zinc, children in low-income settings treated for diarrhoea under WHO guidance, patients with Wilson disease on prescription zinc acetate, and people with genuine deficiency from malabsorption, vegetarian diets high in phytate, or acrodermatitis enteropathica.
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: “Zinc Sulfate Injection is approved for use in the pediatric population, including neonates, as a source of zinc for parenteral nutrition when oral or enteral nutrition is not possible, insufficient, or contraindicated.”
US prescribing information · 95aa8437-10bc-4205-939f-d21d8fa52a00 · read 2026-08-30
On older people, the label states: “Reported clinical experience with intravenous zinc sulfate has not identified a difference in zinc requirements between elderly and younger patients.”
US prescribing information · 95aa8437-10bc-4205-939f-d21d8fa52a00 · read 2026-08-30
On people who are pregnant, the label states: “Risk Summary Administration of the approved recommended dose of Zinc Sulfate Injection in parenteral nutrition is not expected to cause major birth defects, miscarriage, or adverse maternal or fetal outcomes.”
US prescribing information · 95aa8437-10bc-4205-939f-d21d8fa52a00 · read 2026-08-30
On people who are breastfeeding, the label states: “Risk Summary Zinc is present in human milk.”
US prescribing information · 95aa8437-10bc-4205-939f-d21d8fa52a00 · read 2026-08-30
Where the result stopped carrying
Zinc and vitamin C in outpatient COVID-19: 214 patients, stopped early, P = .45
The first two decades of zinc lozenge trials, which were testing doses and formulations that could not release free zinc
Intranasal zinc as a cold remedy, which caused permanent olfactory loss and was withdrawn from the US market in 2009
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.
There was nothing to correct
Where a level is already normal, topping it up may change nothing.
On this record: The best-evidenced use of oral zinc anywhere is childhood diarrhoea in populations where deficiency is common — a repletion effect, not an antiviral one
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.
The product may not be what it says
Contents of a sold product are not always what the label states.
On this record: This is sold as a supplement, so no agency checked what is in a given tub before it was sold.
Other reasons RNAWiki checked and found nothing for (8)
A different form was studied
The studied form is not the form on the shelf. 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.
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
Oral lozenge, tablet, capsule or syrup; formerly also an intranasal gel
✎ 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
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
Sold in the United States as a dietary supplement under DSHEA, so no agency reviewed efficacy or safety before sale.
✎ 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: The lozenge and the swallowed capsule are pharmacologically different interventions: the lozenge acts locally in the oropharynx through free ionic zinc, the capsule acts systemically after ZIP4-mediated absorption, and evidence for one does not transfer to the other. The intranasal route is a third thing again and caused permanent injury. Elemental zinc is a minority of every salt by mass — 36% of zinc acetate, 14% of zinc gluconate — so label doses are not comparable unless the elemental figure is given.
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
Unpleasant taste, nausea and mouth irritation are common with high-dose lozenges and probably compromised blinding in some trials; Cochrane found non-serious adverse events probably increased with treatment zinc at RR 1.34. Sustained high-dose oral zinc induces intestinal metallothionein and causes copper deficiency, presenting as sideroblastic anaemia, neutropenia, or a myelopathy with spastic gait and sensory ataxia in which the haematology reverses on copper replacement and the neurology often does not. Zinc reduces absorption of tetracycline and fluoroquinolone antibiotics and of penicillamine. Intranasal zinc gluconate is directly toxic to olfactory epithelium and should not be used.
Nobody counted how many people took this and were fine, so this cannot be turned into a rate.
Jafek BW, Linschoten MR, Murrow BW. Anosmia after intranasal zinc gluconate use. Am J Rhinol 2004;18:137-141 (15283486) · a recorded source, not a stored snapshot
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 lozenge, tablet, capsule or syrup; formerly also an intranasal gel
✎ 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: The lozenge and the swallowed capsule are pharmacologically different interventions: the lozenge acts locally in the oropharynx through free ionic zinc, the capsule acts systemically after ZIP4-mediated absorption, and evidence for one does not transfer to the other. The intranasal route is a third thing again and caused permanent injury. Elemental zinc is a minority of every salt by mass — 36% of zinc acetate, 14% of zinc gluconate — so label doses are not comparable unless the elemental figure is given.
No source is stored against this line.
What is recorded as being sold
491 products list this as an active ingredient in the United States drug directory. 63 of them contain it and nothing else.
FDA National Drug Code directory · 0517-9302 · read 2026-08-29
They are sold as aerosol, spray, bar, chewable, capsule, capsule, gelatin coated, cream and crystal, taken cutaneous, intravenous, ophthalmic and oral.
FDA National Drug Code directory · 0517-9302 · read 2026-08-29
The regulator's established pharmacologic class for it is copper absorption inhibitor [epc] and decreased copper ion absorption [pe].
FDA National Drug Code directory · 0517-9302 · read 2026-08-29
400 published labels name it as an active ingredient. 30 of them describe this substance alone, which is where its own label text on this page comes from.
US prescribing information · 462c21ba-7304-3606-e063-6294a90aab21 · read 2026-08-29
Those labels are classed as human otc drug and human prescription drug.
US prescribing information · 462c21ba-7304-3606-e063-6294a90aab21 · read 2026-08-29
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
Watching one thing carefully can tell you whether it moved. It cannot tell you what moved it.
This is sold without a prescription, so a person can sensibly watch one thing and see whether it moves.
Pick one goal. One goal only. Two at once cannot be told apart afterwards.
Pick one thing to watch. Registered studies measured things like: lumbar spine bone mineral density by dxa; acute insulin response from ivgtt.
Measure before you start. Take the same measurement several times first. One reading is not a starting point.
Know the swing. Write down how much it moves on its own across a normal week.
Change one thing. Change nothing else at the same time, including training and sleep.
Give it the study length. No finished study window is recorded, so no length is suggested here.
Track whether you took it. Missed days are the most common reason a home test shows nothing.
Read the trend. Look at the line across weeks. A single reading tells you almost nothing.
What not to measure
Anything that swings more day to day than the change you are looking for.
A wearable estimate of sleep stages, which is an estimate and not a measurement.
Weight on one morning, which mostly records water.
A feeling you did not write down before starting.
When to stop
Stop if something new and unpleasant starts, and ask a pharmacist or doctor.
Stop if you cannot keep everything else steady, because the result will not mean anything.
Stop at the end of the window you set, and read the trend then.
Tracking can show whether something changed for you. It cannot show what caused it.
RNAWiki does not work out an amount for anyone.
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 daily zinc supports immunity in a replete adult — the prevention arm of the Cochrane review is null
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 cold benefit transfers across salts and doses, when the entire effect is confined to high-dose acetate and near-acetate formulations
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 AREDS eye result licenses zinc for the general population, when zinc alone missed the prespecified significance level in the full cohort
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 long-term high-dose zinc is harmless, when the same mechanism is an approved copper-blocking drug
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 Zinc 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.
Cochrane 2024: about two days off a cold, at low certainty, and nothing for prevention
In plain words
Thirty-four trials in 8,526 people. Taking zinc once a cold has started may shorten it by roughly two days. Taking it to avoid catching one does nothing.
What was measured
Mean duration of cold in days, proportion developing a cold, and rate of non-serious adverse events
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Thirty-four randomised trials (15 prevention, 19 treatment) in 8,526 participants, 22 in adults and 12 in children. For treatment, mean duration of cold fell by 2.37 days (95% CI -4.21 to -0.53) across 8 studies and 972 participants, but with I-squared of 97% and graded LOW certainty. Whether zinc reduced the risk of still having a cold at end of follow-up was uncertain (RR 0.52, 95% CI 0.21 to 1.27, very low certainty), and global symptom severity showed nothing (SMD -0.03, 95% CI -0.56 to 0.50). For prevention there may be little or no reduction in the risk of developing a cold (RR 0.93, 95% CI 0.85 to 1.01; 9 studies, 1,449 participants; low certainty) and little or no reduction in the number of colds over 5 to 18 months. Non-serious adverse events were probably increased by treatment zinc (RR 1.34, 95% CI 1.15 to 1.55; 16 studies, 2,084 participants; moderate certainty) — the highest certainty grade attached to any treatment finding in the review is the harm, not the benefit.
Written into the record, not signed off as a reviewed claim
Hemila 2011 explained thirty years of contradiction: the dose and the salt
In plain words
Zinc trials had contradicted each other for decades. Splitting them by how much zinc was given resolved it: below a threshold, every trial found nothing; above it, they found a large effect.
What was measured
Pooled percentage reduction in common cold duration, stratified by total daily zinc dose and by zinc salt
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Hemila pooled thirteen placebo-controlled comparisons of zinc lozenges in natural colds. Five trials using a total daily zinc dose below 75 mg uniformly found no effect. Three trials using zinc acetate above 75 mg per day pooled to a 42% reduction in cold duration (95% CI 35% to 48%). Five trials using zinc salts other than acetate above 75 mg per day pooled to a 20% reduction (95% CI 12% to 28%). The conclusion is that the lozenge effect is heterogeneous by design rather than by chance: the negative trials were not failed replications, they were tests of a dose that could not work. The chemistry underneath is that only free ionic zinc is active, and common lozenge excipients such as citric acid, tartaric acid, sorbitol and mannitol chelate it. This is the cleanest example on this site of a field changing its mind not about whether something works but about what "it" was.
Written into the record, not signed off as a reviewed claim
COVID A to Z: 214 patients, stopped early, zinc did nothing
In plain words
A randomised trial of high-dose zinc and vitamin C in outpatients with COVID-19 was halted early because there was no sign either was working.
What was measured
Days to 50% reduction in a composite fever, cough, dyspnoea and fatigue score
Effect estimate
No reviewed effect estimate exists for this record.
Limits
This entry records a failure.
From the source
A multicentre open-label factorial randomised trial at Cleveland Clinic sites in Ohio and Florida enrolled 214 outpatients with PCR-confirmed SARS-CoV-2 between April and October 2020, allocated 1:1:1:1 to ten days of zinc gluconate 50 mg, ascorbic acid 8,000 mg, both, or usual care. The primary endpoint was days to a 50% reduction in a four-symptom severity score. The study was stopped for low conditional power for benefit. Usual care reached 50% symptom reduction at a mean of 6.7 (SD 4.4) days, against 5.9 (4.9) days for zinc, 5.5 (3.7) for ascorbic acid and 5.5 (3.4) for both — overall P = .45, with no significant difference in any secondary outcome. The trial is open-label and was not designed to detect a small effect, but it is the direct randomised test of the exact combination that was being bought by the million during the pandemic.
Written into the record, not signed off as a reviewed claim
Intranasal zinc gluconate causes anosmia, and the causation analysis is formal
In plain words
A homeopathic zinc nasal gel sold for colds destroyed people's sense of smell. In some cases it never came back.
What was measured
Olfactory function after intranasal zinc gluconate exposure
Effect estimate
No reviewed effect estimate exists for this record.
Limits
This entry records a failure.
From the source
Jafek, Linschoten and Murrow reported a case series of severe hyposmia and anosmia following intranasal zinc gluconate, concluding that zinc ions are toxic to olfactory epithelium and that the loss appeared long-lasting or permanent in some cases, with the mechanism attributed to direct action of the divalent zinc ion on the olfactory receptor cell. Davidson and Smith later applied all nine Bradford Hill criteria — strength, consistency, specificity, temporality, biological gradient, plausibility, coherence, experimental evidence and analogy — to 25 patients presenting to the University of California San Diego Nasal Dysfunction Clinic with acute-onset anosmia after intranasal homeopathic zinc gluconate gel, and concluded that the clinical, biological and experimental data support causation. Their stated conclusion was that increased FDA oversight of homeopathic medications is needed. This is a harm caused by route, not by element: the same zinc in a lozenge does not do this.
Written into the record, not signed off as a reviewed claim
Copper depletion: the approved drug action, sold as a side effect nobody mentions
In plain words
High-dose zinc blocks copper absorption. That is not a rare quirk — it is the reason the FDA approved zinc as a prescription drug for a copper-overload disease. In people without that disease it causes anaemia, low white cells and spinal cord damage.
What was measured
That daily high-dose zinc is a benign long-term habit, when the same mechanism is licensed as a copper-blocking drug and its failure mode includes irreversible myelopathy
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Zinc induces metallothionein in the enterocyte; metallothionein binds copper with higher affinity than zinc and holds it until the cell is shed, so copper never reaches the circulation. The FDA approved zinc acetate under NDA 020458 for maintenance therapy in Wilson disease on exactly this mechanism. In people with normal copper handling, Willis et al. reported three cases of zinc-induced copper deficiency first suspected on bone marrow examination: sideroblastic anaemia and severe neutropenia, two of the three with progressive peripheral neuropathy, one of them arising from zinc taken for acrodermatitis enteropathica. Kumar's Mayo Clinic review of copper deficiency myelopathy describes a spastic gait with prominent sensory ataxia that mirrors vitamin B12 subacute combined degeneration, lists excess zinc ingestion among the established causes, and records the crucial asymmetry: copper replacement resolves the anaemia and neutropenia promptly and completely, while neurological improvement is often only subjective and mainly prevents further deterioration.
Written into the record, not signed off as a reviewed claim
AREDS: the eye result everyone cites, where zinc alone missed significance
In plain words
The famous eye trial that put zinc in millions of supplements found the full antioxidant-plus-zinc formula worked. Zinc on its own did not reach the significance bar in the whole group.
What was measured
Odds of photographic progression to advanced AMD and of at least 15-letter visual acuity loss over 6.3 years
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
The Age-Related Eye Disease Study randomised 3,640 participants aged 55 to 80 to antioxidants (vitamin C 500 mg, vitamin E 400 IU, beta carotene 15 mg), zinc 80 mg as zinc oxide with copper 2 mg as cupric oxide, both, or placebo, with average follow-up of 6.3 years and a prespecified significance level of .01. Against placebo, antioxidants plus zinc reduced the odds of progression to advanced AMD (OR 0.72, 99% CI 0.52 to 0.98). Zinc alone gave OR 0.75 (99% CI 0.55 to 1.03) and antioxidants alone OR 0.80 (99% CI 0.59 to 1.09) — neither crossing the threshold in the full cohort. Excluding the 1,063 lowest-risk participants, whose five-year probability of progression was only 1.3%, zinc alone reached OR 0.71 (99% CI 0.52 to 0.99). The only significant reduction in at least moderate visual acuity loss was in the combined arm (OR 0.73, 99% CI 0.54 to 0.99). Two facts the supplement aisle rarely carries forward: the benefit was confined to people already at high risk, and copper was included in the formulation specifically to offset zinc-induced copper deficiency.
Written into the record, not signed off as a reviewed claim
Childhood diarrhoea: the strongest zinc evidence anywhere, and it is age-limited
In plain words
In children over six months old, zinc shortens acute diarrhoea by about half a day, and by a full day in malnourished children. In babies under six months it does nothing.
What was measured
Mean duration of acute diarrhoea in hours, and proportion with diarrhoea persisting to day seven
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Thirty-three trials in 10,841 children, mostly in Asian settings at high risk of zinc deficiency. In children older than six months, zinc shortened mean diarrhoea duration by 11.46 hours (95% CI -19.72 to -3.19; 2,581 children, 9 trials, low certainty) and probably reduced the proportion whose diarrhoea persisted to day seven (RR 0.73, 95% CI 0.61 to 0.88; 3,865 children, 6 trials, moderate certainty). In children with signs of malnutrition the effect was larger and the certainty higher: 26.39 hours shorter (95% CI -36.54 to -16.23; 419 children, 5 trials, HIGH certainty). In children younger than six months the evidence suggests no effect on mean duration. There was not enough evidence to say whether zinc reduces death or hospitalisation. The pattern is the same one that runs through this whole file: the effect is largest where the deficiency is real, and disappears where it is not.
This order is fixed in code and does not count clicks or time on the page.
What is not here
4 questions this page could not answer
These sections were prepared and left out because there was nothing to put in them. They are listed rather than hidden, so the gaps in this record are visible.
How long anything takes — found nothing in the sources checked.
What it may clash with — found nothing in the sources checked.
Other ways to the same goal — found nothing in the sources checked.
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.
Zinc lozenges probably do shorten a cold, but only above about 75 mg per day and best as the acetate salt, which is why half the trials found nothing; the prevention claim is null across 1,449 participants, and the two documented harms — permanent anosmia from nasal gels and copper deficiency from sustained high oral intake — are real and undersold.
Recorded evidence blocks (14)
Q1
What did Zinc's largest trial (8000 people) and its longest (16 years) measure?
8000 people in Zinc's largest registered study, 16 years in its longest registered window, measuring Progression of age-related macular degeneration. ClinicalTrials.gov · 2026-09-01
54 na, 45 phase3, 39 phase2, 28 phase4, 10 phase1, 5 na or unstated, 2 early phase1; NCT00000145; 2006-12. Last human test completed 2026, NCT07383363.
Interpretation These counts include studies where Zinc 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
na
54
phase3
45
phase2
39
phase4
28
phase1
10
na or unstated
5
2 more recorded rows
early phase1
2
Last recorded human testNCT07383363
2026-03-30
recorded 2026-09-01 · last checked 2026-09-04
Q2
From yeast to human: where has Zinc shown lifespan?
16 recorded entries; human; tablet; also "Zinc sulphate (20 mg)", "Zinc (12.5 mg/day)", "Zinc sulphate 20 mg"
Show the evidence
human
NCT00104494
Zinc acetate (20mg/d)
NCT00142285
Zinc sulphate (20 mg)
NCT00228254
Zinc (12.5 mg/day)
NCT00355043
Zinc sulphate 20 mg
NCT02072746
Zinc sulfate 220 mg
NCT03005496
Zinc Picolinate 50 mg
10 more recorded rows
humanNCT03135522
Zinc Acetate 50 Mg Oral Capsule
humanNCT03824925
Zinc Sulfate 220 MG
humanNCT04321850
Zinc Sulfate 50 Mg Tab
humanNCT04899843
tablet; Zinc sulphate tablet 20 mg
humanNCT05178953
Zinc Sulfate 220 mg Capsules
humanNCT05190562
Zinc Sulfate 110 MG (Zinc 25 MG) Oral Tablet
humanNCT05894109
zinc citrate 50 mg
humanNCT06290219
Zinc Gluconate 10 MG Oral Tablet
humanNCT06412653
WILZIN 25mg
humanNCT06412653
WILZIN 50mg
recorded 2026-09-01 · last checked 2026-09-04
Q5
Did Zinc move Horvath, and by how much?
Horvath: "A one standard deviation increase in individual essential metals (copper, manganese, and zinc) was associated with 0.94-1.2 weeks lower Horvath EAA at birth, and patterns of exposures identified by exploratory factor analysis suggested that a common source of essential metals was associated with Horvath EAA." Europe PMC · epigenetic clock search · 2026-06-01
3 recorded sentences; 2024, 2026; biomarker
Show the evidence
Horvath
PMID 38412256
2024; "A one standard deviation increase in individual essential metals (copper, manganese, and zinc) was associated with 0.94-1.2 weeks lower Horvath EAA at birth, and patterns of exposures identified by exploratory factor analysis suggested that a common source of essential metals was associated with Horvath EAA."
PMID 38412256
2024; "We also observed evidence nonlinear associations of zinc with Bohlin EGAA, magnesium and lead with Horvath EAA, and cesium with skin and blood EAA at birth."
epigenetic agePMID 41875434
2026; "We evaluated exposure to high ambient temperatures and sperm epigenetic age among 1,220 men residing along the Wasatch Front in Utah in an ancillary prospective cohort study set within the Folic Acid and Zinc Supplementation Trial (FAZST; 2013-2018)."
recorded 2026-06-01 · last checked 2026-09-04
Q6
More Zinc was worse in human: at what point?
U-shaped in human: "Dose-response analysis based on restricted cubic splines revealed nonlinear patterns: blood cadmium exhibited a U-shaped dose-response relationship (P non-linear = 0.005) with risk rising markedly above 3.5 µg/L, and dietary zinc showed a J-shaped curve (P non-linear = 0.004) peaking around 22 mg/day." Europe PMC · dose-response search · 2026-08-07
6 recorded sentences naming Zinc; U-shaped, hormesis, hormetic
Show the evidence
U-shaped
PMID 42566870
"Dose-response analysis based on restricted cubic splines revealed nonlinear patterns: blood cadmium exhibited a U-shaped dose-response relationship (P non-linear = 0.005) with risk rising markedly above 3.5 µg/L, and dietary zinc showed a J-shaped curve (P non-linear = 0.004) peaking around 22 mg/day."
PMID 42524553
"RCS analysis demonstrated linear protective trends for calcium, phosphorus, zinc, potassium, and selenium, while magnesium, iron, and copper exhibited U-shaped dose-response patterns."
PMID 42126678
"Selenium showed a protective effect (Q4 vs. Q1: OR = 0.49, 95% CI: 0.32-0.73), while zinc displayed a non-linear, U-shaped relationship."
hormesisPMID 41343535
"Our results indicate that foliar application of zinc oxide nanoparticles is a viable strategy for reducing Cd accumulation in lettuce and other leafy vegetables under Cd-induced hormesis, thereby ensuring food safety."
hormetic
PMID 41166048
"All fungi exhibited a hormetic response to zinc, evidenced by increased biomass and stimulated sporulation."
PMID 41166048
"These collective findings suggest a predominantly hormetic, rather than a stress-induced, response to zinc exposure."
recorded 2026-08-07 · last checked 2026-09-04
Q7
Could one person measure Zinc's effect on progression of age related macular degeneration?
Progression of age related macular degeneration: measured in Zinc's trials.
Interpretation progression of age related macular degeneration is the recorded endpoint.
Show the evidence
biomarkers
progression of age related macular degeneration; 2026-09-01
progression of lens opacity; 2026-09-01
infant maize/zn supplementation trial; 2026-09-01
linear growth velocity; 2026-09-01
zn homeostasis studies; 2026-09-01
m at 1 5 months; 2026-09-01
14 more recorded rows
biomarkers
duration of illness; 2026-09-01
biomarkers
treatment failure; 2026-09-01
biomarkers
risk of treatment failure; 2026-09-01
biomarkers
adverse effects; 2026-09-01
biomarkers
immune failure; 2026-09-01
biomarkers
duration of severe symptoms; 2026-09-01
biomarkers
adverse events and serious adverse events; 2026-09-01
biomarkers
reduction in duration of diarrhoea; 2026-09-01
biomarkers
reeudction in total stool volume; 2026-09-01
biomarkers
incidence of acute lower respiratory infection; 2026-09-01
biomarkers
growth; 2026-09-01
biomarkers
time to cessation of severe pneumonia; 2026-09-01
biomarkers
illnesses requiring visits to healthcare providers; 2026-09-01
biomarkers
stool output; 2026-09-01
human trials at or under30
23
Not recorded for this substance
a recorded half-life
smallest human trial
0; NCT04528927; PHASE3; the smallest recorded human enrolment at or below 30; the registry states no direction of its result; WITHDRAWN
Q8
Which of acute insulin response from ivgtt, adverse effects and adverse events and serious adverse events did Zinc's trials measure?
acute insulin response from ivgtt, adverse effects and adverse events and serious adverse events lead 40 outcome terms across Zinc's trials. ClinicalTrials.gov · 2026-09-01
linear growth velocity, zn homeostasis studies, m at 1 5 months, duration of illness, treatment failure and risk of treatment failure follow.
Show the evidence
progression of age related macular degeneration
1
progression of lens opacity
1
infant maize/zn supplementation trial
1
linear growth velocity
1
zn homeostasis studies
1
m at 1 5 months
1
14 more recorded rows
duration of illness
1
treatment failure
1
risk of treatment failure
1
adverse effects
1
immune failure
1
duration of severe symptoms
1
adverse events and serious adverse events
1
reduction in duration of diarrhoea
1
reeudction in total stool volume
1
incidence of acute lower respiratory infection
1
growth
1
time to cessation of severe pneumonia
1
illnesses requiring visits to healthcare providers
"Effect of Probiotic and Zinc Supplementations on the Clinical Outcome in Pediatric Patients with Ventriculitis"; n 140; "CSF culture"; 2025-12
NCT06517862
"Efficacy & Safety of Oral Adjuvants to Phototherapy in Neonatal Hyperbilirubinemia"; n 80; "serum bilirubin level."; 2026-06-30
NCT06567717
"Zinc and Nicotinamide Riboside for Idiopathic Pulmonary Fibrosis"; n 60; "Feasibility of Retention"; 2027-01
NCT06588036
"A Comprehensive Analysis of the Comparative Efficacy of Multimodal Diarrhea Therapies in the Paediatric Population"; n 100; "resolution of diarrhea"; 2024-12-30
NCT06612554
"Zn Supplementation in HIV Immunological Non Responders"; n 120; "CD4+ T-cell number change"; 2026-12
NCT06664008
"The Effect of Probiotic and Zinc Supplementation in Patients With Gastroesophageal Reflux Disease"; n 120; "Change in Gastrointestinal Symptom Rating Scale (GSRS)"; 2025-10-01
7 further recorded trials
NCT06674564
"Effect of Zinc and Probiotics Supplementation on Laryngeal Cancer Patients Undergoing Laryngectomy Surgery to Improve Prognosis and Better Wound Healing"; n 140; "wound healing"; 2026-10
NCT07102836
"COMPARISON OF ZINC AND PROBIOTICS ON NEONATES WITH INDIRECT HYPERBILIRUBINEMIA UNDERGOING PHOTOTHERAPY"; n 110; "Rate of decline in Bilirubin levels during phototherapy with this adjuvant therapy"; 2026-05-07
NCT07140874
"Zinc as an Adjunctive Therapy for Cervical Dystonia"; n 25; "Duration of Botox efficacy"; 2027-05-31
NCT07145268
"Zinc Sulphate in Treatment Fibrosis in HBV Patient Receiving Antiviral Therapy"; n 44; "Change in fibrosis scores."; 2026-09
NCT07275827
"Comparative Study Evaluating Safety and Effectiveness of ( Proton Pump Inhibitor Versus Vonoprazan ) Based Triple Therapy With or Without Zinc to Eradicate H. Pylori Infection"; n 88; "Serum interleukin-6 (IL-6) level: will be assessed by ELISA"; 2026-10
NCT07367412
"Zinc Supplementation and Infections in Older Medical Patients"; n 8000; "Days Alive and Out of Hospital"; 2028-03-15
NCT07405554
"Zinc Supplementation With Botulinum Toxin for Overactive Bladder"; n 72; "Number of patients needing repeat intradetrusor botulinum toxin injection at 6 months"; 2026-12
recorded 2026-09-01 · last checked 2026-09-04
Q10
Which running trial of Zinc could settle inflammatory markers?
NCT07275827 measures Serum interleukin-6 (IL-6) level: will be assessed by ELISA, reading out 2026-10.
1 open trial; n 88; "Comparative Study Evaluating Safety and Effectiveness of ( Proton Pump Inhibitor Versus Vonoprazan ) Based Triple Therapy With or Without Zinc to Eradicate H. Pylori Infection"
Show the evidence
TrialNCT07275827
"Comparative Study Evaluating Safety and Effectiveness of ( Proton Pump Inhibitor Versus Vonoprazan ) Based Triple Therapy With or Without Zinc to Eradicate H. Pylori Infection"; n 88; "Serum interleukin-6 (IL-6) level: will be assessed by ELISA"; 2026-10
Q11
Which 97 trials of Zinc posted no result?
Posted no result
97 of 97 completed trials
Registrations
NCT00226616, NCT00228254, NCT00198666, NCT00212368, NCT00325247 and NCT00408356, and 91 more
Completion dates
oldest 2002-07; newest 2024-05-31
Show the evidence
Trial
NCT00226616
2002-07
NCT00228254
2004-06
NCT00198666
2004-08
NCT00212368
2005-12
NCT00325247
2006-05
NCT00408356
2006-11
14 further recorded trials
NCT00000145
2006-12
NCT00370968
2006-12
NCT00149552
2007-01
NCT00373100
2007-03
NCT00098202
2007-04
NCT00036881
2007-06
NCT00272142
2007-08
NCT00104494
2007-09
NCT00355043
2007-09
NCT00459485
2007-12
NCT01166815
2008-01
NCT00682955
2008-04
NCT00142285
2008-05
NCT00252304
2008-07
Q12
At the median, Zinc's trials enrolled 100 people — anything larger?
Median enrolment
100
Largest enrolment
8000
Registered trials counted
164
Q13
Was Zinc studied with exercise?
exercise is named in Zinc's label sentences: "Healthy pregnant women were randomized to four groups: exercise (<i>n</i> = 19), AMS (zinc/magnesium/tocopherol/vitamin C/niacin) (<i>n</i> = 19), exercise plus AMS (<i>n</i> = 19), and controls (<i>n</i> = 20)." openfda-label+europepmc · 2025-07-09
1 recorded statement; exercise
Show the evidence
exercise
Healthy pregnant women were randomized to four groups: exercise (<i>n</i> = 19), AMS (zinc/magnesium/tocopherol/vitamin C/niacin) (<i>n</i> = 19), exercise plus AMS (<i>n</i> = 19), and controls (<i>n</i> = 20).
recorded 2025-07-09 · last checked 2026-09-04
Q14
What is recorded about Zinc and mTOR?
"The included studies suggest that cardiomyocyte death induced by SIMD might be partially regulated by autophagy and its associated genes and pathways, including but not limited to Unc-51 like-autophagy-activating kinase 1 (ULK1), Zinc finger antisense 1 (ZFAS1), miR-590-3p, miR-214-3p, miR-21-3p, Silent information regulator 1 (SIRT1),…" — where Zinc and mTOR appear together. Europe PMC · pathway abstract search · 2026-07-08
"The included studies suggest that cardiomyocyte death induced by SIMD might be partially regulated by autophagy and its associated genes and pathways, including but not limited to Unc-51 like-autophagy-activating kinase 1 (ULK1), Zinc finger antisense 1 (ZFAS1), miR-590-3p, miR-214-3p, miR-21-3p, Silent information regulator 1 (SIRT1), SH3 domain-containing protein 2 (SORBS2), AMP-activated…"
AMPKPMID 41676277
"The included studies suggest that cardiomyocyte death induced by SIMD might be partially regulated by autophagy and its associated genes and pathways, including but not limited to Unc-51 like-autophagy-activating kinase 1 (ULK1), Zinc finger antisense 1 (ZFAS1), miR-590-3p, miR-214-3p, miR-21-3p, Silent information regulator 1 (SIRT1), SH3 domain-containing protein 2 (SORBS2), AMP-activated…"
sirtuinPMID 41676277
"The included studies suggest that cardiomyocyte death induced by SIMD might be partially regulated by autophagy and its associated genes and pathways, including but not limited to Unc-51 like-autophagy-activating kinase 1 (ULK1), Zinc finger antisense 1 (ZFAS1), miR-590-3p, miR-214-3p, miR-21-3p, Silent information regulator 1 (SIRT1), SH3 domain-containing protein 2 (SORBS2), AMP-activated…"
autophagyPMID 41676277
"The included studies suggest that cardiomyocyte death induced by SIMD might be partially regulated by autophagy and its associated genes and pathways, including but not limited to Unc-51 like-autophagy-activating kinase 1 (ULK1), Zinc finger antisense 1 (ZFAS1), miR-590-3p, miR-214-3p, miR-21-3p, Silent information regulator 1 (SIRT1), SH3 domain-containing protein 2 (SORBS2), AMP-activated…"
AMPKPMID 42415176
"We previously identified 1H10 as an AMP-activated protein kinase (AMPK) inhibitor and subsequently demonstrated its zinc-binding capacity and ability to regulate intracellular zinc homeostasis."
autophagy
PMID 42415176
"Building on our prior findings that intra-lysosomal zinc promotes acidification and activates transcription factor EB (TFEB), we investigated whether 1H10 enhances lysosomal function through zinc mobilization in neurons, thereby improving autophagy and reducing pathological protein accumulation."
PMID 42415176
"These findings indicate that zinc-mediated lysosomal activation by 1H10 enhances the autophagy-lysosomal pathway and attenuates tau pathology in AD models, suggesting that targeting lysosomal function may represent a potential therapeutic strategy for neurodegenerative disorders characterized by impaired proteostasis."
AMPKPMID 42260976
"Collectively, these findings revealed that viruses weaponized the moonlighting function of a metabolic enzyme to dismantle autophagic flux, highlighting PHGDH as a broad-spectrum antiviral target that bridged metabolism and membrane trafficking.<b>Abbreviation:</b> AMPK: AMP-activated protein kinase; BECN1: beclin 1; CQ: chloroquine; MAP1LC3/LC3: microtubule associated protein 1 light chain 3;…"
sirtuinPMID 41454179
"The latter may be mediated by inhibition of SIRT1/SIRT3 activity, as well as modulation of PINK1/ zinc finger protein 746 (ZNF746)/PGC-1α axis."
mTORPMID 42047332
"Exploring the intricate molecular interplay between natural products and autophagy in limiting infections may provide valuable insights that could inform the development of innovative host-directed antimicrobial treatments based on autophagy regulation.<b>Abbreviations:</b> 3-MA: 3-methyladenine; AM: alveolar macrophages; AMP: antimicrobial peptides; AMPK: 5' adenosine monophosphate-activated…"
sirtuinPMID 42047332
"Exploring the intricate molecular interplay between natural products and autophagy in limiting infections may provide valuable insights that could inform the development of innovative host-directed antimicrobial treatments based on autophagy regulation.<b>Abbreviations:</b> 3-MA: 3-methyladenine; AM: alveolar macrophages; AMP: antimicrobial peptides; AMPK: 5' adenosine monophosphate-activated…"
NAD+PMID 42209503
"Finally, we evaluate emerging mitochondria-targeted rejuvenation strategies, NAD⁺ repletion, mitophagy enhancers, mitochondrial transplantation/engineering, and precision elimination of mutant mtDNA using mitochondria-targeted transcription activator-like effector nucleases (mitoTALENs) or zinc-finger nucleases (mitoZFNs), emphasizing tissue-specific thresholds and context dependence for…"
mTORPMID 40873286
"Zinc acts via various signaling pathways, such as AMPK and mTOR, and influences lipid and glucose metabolism."
1 more recorded row
NAD+PMID 42024581
"Zinc ions inhibit SARM1 activity by coordinating with a conserved C<sub>2</sub>H<sub>2</sub> motif in the SS loop, thereby restricting His640 flipping and preventing NAD engagement."
recorded 2026-07-08 · last checked 2026-09-04
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