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Melatonin

  • Hormone
  • Varies by country
  • Identity checked
  • Sources last checked 2026-09-04

This page shows what was measured, who it was measured in, and what that does not settle.

What Melatonin does in the body

Taken to fall asleep faster, and to reset the clock after flying

When the light fades, a gland in your brain releases melatonin into the blood, and receptors on the master clock read that as the signal that night has started. Swallowing melatonin adds that signal at whatever hour you take it, which nudges the clock — forward if taken in the evening, backward if taken in the morning. It also has a mild direct drowsiness effect at the right moment in the evening. What it does not do is sedate you the way a sleeping pill does, which is why people who expect a knockout are disappointed and people who use it to move a body clock across time zones tend not to be.

What happened in people

Sleep onset latency fell by 7.06 minutes and total sleep time rose by 8.25 minutes across 19 trials in 1,683 people

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.

The limit that matters most

The effect on ordinary insomnia is real, replicated, and small — and unusually, it does not fade with continued use

Where it acts
Suprachiasmatic nucleus of the hypothalamus, where MT1 and MT2 receptors are densest; also retina, pars tuberalis and peripheral vasculature
Kind of result
Symptoms and quality of life
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 substance registry classes this as chemical.

    FDA substance registry · JL5DK93RCL · read 2026-08-29

  • The supplement label database classes it as hormone, under the name Melatonin.

    NIH Dietary Supplement Label Database · 517 · read 2026-08-29

Where each sentence above came from

No recorded sentence describes the change this makes in a way that stands on its own. The page opens with what it is taken for instead, and the recorded explanation follows below.

Shown as the opening line on this page.

A limit recorded against this substance. Not signed off as a reviewed claim.

The four opening statements run to 150 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 peopleRead 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.
GoalLife outcomeWhat a body can doHow a person feelsA test resultA step in the bodyHarmsHow longWho was studied
SleepNothing 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.Waiting for a reviewer2 registered symptom measure.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.
PainNothing 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.Waiting for a reviewer1 registered symptom measure.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.
MoodNothing 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.Waiting for a reviewer1 registered symptom measure.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.
EnergyNothing 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.Waiting for a reviewer1 registered symptom measure.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.
MuscleNothing 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.
Blood sugarNothing 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.
Body weightNothing 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.
Healthy ageingWaiting for a reviewer1 registered study measure of this kind. No reviewed result yet.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.
Which registered measures put each goal on this table
Sleep
sleep quality; sleep efficiency; sleep duration; total sleep time; sleep; pittsburgh sleep quality index change
Pain
pain; time to first requirement of analgesic supplement
Mood
anxiety; intention to treat depression at one in the study period
Energy
fatigue
Muscle
gain in lean body mass
Blood sugar
glucose tolerance
Body weight
weight change
Healthy ageing
mortality

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.
Waiting for a reviewer
2 registered symptom measure.
Not recorded
Harms were not a registered measure for this goal.
Only a number moved
1 registered test measure.

What happened in peopleRead 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.

Sleep onset latency, total sleep time and sleep quality versus placebo

The study showed what it set out to show

Who was studied
Ferracioli-Oda 2013 meta-analysis of melatonin in primary sleep disorders
How many people
1683
Study design
Meta-analysis of 19 randomised placebo-controlled trials
Compared against
A dummy treatment
Kind of result
A number that stands in for health
What was found
Sleep latency WMD -7.06 min (95% CI 4.37 to 9.75), P < 0.001; total sleep time +8.25 min (95% CI 1.74 to 14.75), P = 0.013; sleep quality SMD 0.22, P < 0.001
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. The authors state the absolute benefit is smaller than that of other pharmacological insomnia treatments. Effects were dose- and duration-dependent for latency but not for sleep quality, which argues the quality finding is not a pharmacological dose-response.

How far it carries. This study is recorded from the curated record, not from the registry match.

Form and route. Oral tablet, capsule, gummy, liquid or spray; prolonged-release tablet as an EU prescription medicine

Interval reported. 95% CI 4

Written into the record, not signed off as a reviewed claim.

Sleep onset latency, total sleep duration and sleep efficiency

The study showed what it set out to show

Who was studied
Brzezinski 2005 meta-analysis of exogenous melatonin on sleep
How many people
284
Study design
Meta-analysis of 17 studies
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Sleep onset latency -4.0 min (95% CI 2.5 to 5.4); sleep efficiency +2.2% (95% CI 0.2 to 4.2); total sleep duration +12.8 min (95% CI 2.9 to 22.8)
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. The included studies were highly heterogeneous in inclusion criteria, insomnia measures, dose and route, which the authors state explicitly as the reason the field had been unable to agree.

How far it carries. This study is recorded from the curated record, not from the registry match.

Form and route. Oral tablet, capsule, gummy, liquid or spray; prolonged-release tablet as an EU prescription medicine

Interval reported. 95% CI 2

Written into the record, not signed off as a reviewed claim.

Polysomnographic sleep efficiency across 0.1, 0.3 and 3.0 mg doses

The study showed what it set out to show

Who was studied
Zhdanova 2001 — dose-ranging melatonin in age-related insomnia
How many people
30
Study design
Double-blind placebo-controlled randomised crossover with polysomnography
Compared against
A dummy treatment
Kind of result
A number that stands in for health
What was found
Sleep efficiency restored at 0.3 mg, P < 0.0001; plasma melatonin normalised at 0.3 mg, P < 0.0008
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. The 3.0 mg dose induced hypothermia and left plasma melatonin elevated into daylight hours. Normal-sleeping controls with equally low melatonin levels showed no benefit at any dose, which argues the effect is repletion in a specific phenotype rather than a general hypnotic action.

How far it carries. This study is recorded from the curated record, not from the registry match.

Form and route. Oral tablet, capsule, gummy, liquid or spray; prolonged-release tablet as an EU prescription medicine

Interval reported. Not recorded in this summary

Written into the record, not signed off as a reviewed claim.

Proportion reporting significant improvement in sleep quality and next-day functioning at three weeks

The study showed what it set out to show

Who was studied
Circadin EU registration programme (EMEA/H/C/000695)
How many people
681
Study design
Three randomised placebo-controlled trials supporting marketing authorisation
Compared against
A dummy treatment
Kind of result
What a body can do day to day
What was found
32% on Circadin (86/265) versus 19% on placebo (51/272)
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. The authorised indication is deliberately narrow: monotherapy, short-term, primary insomnia, age 55 or over, prescription only, up to 13 weeks. None of those restrictions exist for the identical molecule sold over the counter in the United States.

How far it carries. This study is recorded from the curated record, not from the registry match.

Form and route. Oral tablet, capsule, gummy, liquid or spray; prolonged-release tablet as an EU prescription medicine

Interval reported. Not recorded in this summary

Written into the record, not signed off as a reviewed claim.

Measured melatonin content as a percentage of labelled quantity

The study did not show it

Who was studied
Cohen 2023 — quantity of melatonin and CBD in US melatonin gummies
How many people
25
Study design
Analytical survey of marketed products
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Melatonin content 74% to 347% of label; only 3 of 25 within plus or minus 10%; one product contained no melatonin and 31.3 mg CBD
Repeated elsewhere
Replicated

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. CBD content in the five CBD-containing products was accurate at 104% to 118% of label, which removes analytical difficulty as an explanation for the melatonin failures.

How far it carries. This study is recorded from the curated record, not from the registry match.

Form and route. Oral tablet, capsule, gummy, liquid or spray; prolonged-release tablet as an EU prescription medicine

Interval reported. Not recorded in this summary

Written into the record, not signed off as a reviewed claim.

What we know
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 peopleRead 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.

  1. Living longer, or avoiding a major event Evidence recorded. Death, a heart attack, a stroke, a hospital stay.2 registered measures of this kind. No reviewed result.
  2. What a body can do day to day No evidence recorded. Walking, dressing, breathing, recovering.No registered study measures this.
  3. Measured performance No evidence recorded. How much was lifted, how far was run, how fast.No registered study measures this.
  4. Symptoms and quality of life Evidence recorded. Pain, tiredness, mood, sleep, as the person rated it.7 registered measures of this kind.
  5. A number that stands in for health Evidence recorded. Cholesterol, blood sugar, bone density. A stand-in, not the thing itself.5 registered measures of this kind.
  6. A step measured inside a person Evidence recorded. Something measured in human tissue or human cells.A human record sits on the stored organism ladder.
  7. Animals Evidence recorded. Mice, rats, dogs. Useful for ideas, not proof about people.Stored records in C. elegans (roundworm), Drosophila (fruit fly), Mouse, Rat, Dog, Non-human primate. A result in animals says what to test next. It does not say what happens in people.
  8. Cells in a dish Evidence recorded. Cells or chemistry on a bench, far from a whole body.Stored mechanism abstracts describe steps measured in cells or tissue.
  9. A guess from software No 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 bodyRead 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.

  1. Start

    Melatonin

    What a person takes: Oral tablet, capsule, gummy, liquid or spray; prolonged-release tablet as an EU prescription medicine.

    The measurement behind this step

    Sold in the United States as a dietary supplement under DSHEA, so no agency reviewed efficacy, safety or content before sale. In the European Union, the United Kingdom, Australia, Canada and Japan the same molecule is a medicine requiring a prescription or pharmacist supply. Immediate-release and prolonged-release products are pharmacokinetically different interventions and their trial evidence is not interchangeable. Gummy formats are the fastest-growing and the worst-characterised: they are the format at the centre of both the content-accuracy failure and the paediatric ingestion epidemic.

  2. Getting in

    Darkness starts the signal, and light stops it

    Special cells in the retina report ambient light straight to the body's master clock. When light falls, the clock releases the brake on the pineal gland and melatonin rises.

    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

    Melanopsin-expressing intrinsically photosensitive retinal ganglion cells project through the retinohypothalamic tract to the suprachiasmatic nucleus, which controls pineal melatonin synthesis through a multisynaptic pathway ending in sympathetic input to the pineal. Evening short-wavelength light suppresses release. Dim-light melatonin onset, measured under sub-10-lux conditions, is the reference standard for circadian phase precisely because it is the least contaminated marker available.

  3. Reaching the cell

    Swallowed melatonin overshoots the natural peak by a wide margin

    Night-time melatonin in the blood is a very small quantity. A typical retail tablet produces far more than that, and keeps producing it for hours.

    Measured in people. Written by a person from the study named beside the step. Not signed off as a reviewed claim.

    The measurement behind this step

    Physiological nocturnal plasma melatonin peaks in the tens to low hundreds of picomolar. Zhdanova showed that 0.3 mg was sufficient to restore that range and restore sleep efficiency in older insomniacs, while 3.0 mg induced hypothermia and left plasma melatonin elevated into daylight hours. Oral melatonin also undergoes extensive first-pass CYP1A2 metabolism, which is highly variable between individuals and is inhibited by fluvoxamine and by caffeine.

  4. What it acts on

    It binds two receptors on the clock itself

    Melatonin docks onto two specific receptors concentrated in the small cluster of cells that runs the body's daily timing. One quietens those cells; the other moves the clock.

    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

    MT1 (MTNR1A) and MT2 (MTNR1B) are Gi-coupled receptors densely expressed in the suprachiasmatic nucleus. MT1 activation acutely suppresses SCN neuronal firing; MT2 mediates phase shifts. Both inhibit adenylyl cyclase and lower cAMP. MT2 internalises and desensitises under sustained agonist exposure, which is why a large dose held high for many hours is not a scaled-up version of the physiological pulse.

  5. The change it makes

    The clock moves in a direction that depends entirely on when you took it

    Evening melatonin pulls the clock earlier. Morning melatonin pushes it later. Take it at the wrong hour and it makes the problem worse rather than better.

    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 melatonin phase-response curve is roughly opposite in shape to the light phase-response curve. Administration in the hours before habitual dim-light melatonin onset advances phase; administration in the late night or early morning delays it. This is why the jet lag evidence is strong and direction-specific, and why an insomnia trial that ignores timing is measuring a hypnotic effect that melatonin barely has instead of a chronobiotic effect it clearly does.

  6. What that does for a person

    The measurable result is minutes, not hours

    Pooled across nineteen trials, melatonin got people to sleep about seven minutes sooner and kept them asleep about eight minutes longer. That is a real effect and a small one.

    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

    Weighted mean difference in sleep onset latency 7.06 minutes (95% CI 4.37 to 9.75) and total sleep time 8.25 minutes (95% CI 1.74 to 14.75), with a sleep quality standardised mean difference of 0.22. The authors of that meta-analysis noted that the absolute benefit is smaller than other pharmacological insomnia treatments but does not dissipate with continued use — an unusual and genuinely favourable property.

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 takeRead 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.

  • fatigue
  • sleep quality
  • clinical global impression improvement
  • pain
  • anxiety
  • quality of life
  • pittsburgh sleep quality index change

Measured

Things only a test, a scale or a device shows.

  • increase in heart rate standing
  • gain in lean body mass
  • changes in bone mineral density
  • glucose tolerance
  • weight change

Meaningful

Things that change how a life goes, not only a number.

  • mortality
  • progression free survival

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 (26)
  • improvement in jet lag symptoms
  • luteinizing hormone
  • infarct size
  • sleep efficiency
  • migraine attack frequency
  • sleep duration
  • total sleep time
  • incidence of postoperative delirium
  • relapses
  • edss
  • intention to treat depression at one in the study period
  • headache days from baseline to month 3 after treatment
  • abnormal involuntary movement scale
  • adhd symptoms improvement
  • oxidative stress
  • time to first requirement of analgesic supplement
  • incontinence episodes
  • sleep
  • compliance
  • primary objective

These are harms, study-process measures, or names the rules did not recognise. They are shown rather than dropped.

What it would be like to takeRead from sources, not yet reviewed

How long anything takes

Nine different lengths of time that get confused with each other. None of them is worked out from another.

  1. Before anything is noticed. RNAWiki does not store this separately, and never works it out from another figure on this page.

  2. Before a test result moves. RNAWiki does not store this separately, and never works it out from another figure on this page.

  3. Before performance moves. RNAWiki does not store this separately, and never works it out from another figure on this page.

  4. How long the result was watched. No finished study window is recorded for a study that tested this substance.

  5. How long people took it. How long people actually took it is not stored. The study window is not the same thing.

  6. How long people were followed. Follow-up length is not stored separately. It is never read off the study window, which would be a different thing.

  7. How fast the body clears it. mean 53.7 minutes minutes

    Read from the label, which states: “Mean t 1/2 elimination was 53.7 (7.0) min. Median absolute bioavailability was 2.5 (1.7-4.7) %.”

  8. How long effects linger. RNAWiki does not store this separately, and never works it out from another figure on this page.

  9. Beyond the studies. Nothing is recorded about the long term.

    The longest finished study sets the edge of what anyone measured.

A study window is not how long people took it, and neither is how long they were followed. Where RNAWiki holds only one of the three, it shows one.

What is missing or unclearRead 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 with insomnia, shift workers, travellers crossing time zones, people with delayed sleep-wake phase disorder, blind people with non-24-hour rhythms, and — increasingly and without good evidence for long-term use — children, often given it by parents.

Who is missing from the studies

  • Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.

Where the result stopped carrying

  • Insomnia trials that ignored administration timing, which measured a hypnotic effect melatonin barely has instead of the chronobiotic effect it clearly does
  • The US supplement content control regime, which permitted a 4.7-fold spread around label across a single product category
  • 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 takeRead from sources, not yet reviewed

Why it might seem to do nothing

A real effect and a noticed effect are different things. These are the recorded reasons the two come apart.

It was studied for a different goal

The studies measured something else entirely.

On this record: Some registered studies measured things that match no goal on this page.

It was studied in different people

The people in the studies were not much like the reader.

On this record: Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.

The evidence may simply be wrong

Small early studies often do not hold up.

On this record: RNAWiki has not yet published a reviewed conclusion for this use.

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 (9)
A different form was studied
The studied form is not the form on the shelf. Nothing in this record points to this reason.
There was nothing to correct
Where a level is already normal, topping it up may change nothing. Nothing in this record points to this reason.
Something else had to happen too
In the studies it was paired with training, a diet or another treatment. Nothing in this record points to this reason.
The change is too small to feel
A real change can still sit below what a person notices. Nothing in this record points to this reason.
Day-to-day swing hides it
Sleep, food, stress and time of day move most numbers more than this would. Nothing in this record points to this reason.
Not enough time yet
The studies ran longer than the person has waited. Nothing in this record points to this reason.
It was not taken as studied
Missed days change the result, and studies count them. Nothing in this record points to this reason.
Something else changed at the same time
Two changes at once cannot be told apart afterwards. Nothing in this record points to this reason.
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 takeRead 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 tablet, capsule, gummy, liquid or spray; prolonged-release tablet as an EU prescription medicine

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, safety or content before sale. In the European Union, the United Kingdom, Australia, Canada and Japan the same molecule is a medicine requiring a prescription or pharmacist supply. Immediate-release and prolonged-release products are pharmacokinetically different interventions and their trial evidence is not interchangeable. Gummy formats are the fastest-growing and the worst-characterised: they are the format at the centre of both the content-accuracy failure and the paediatric ingestion epidemic.

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 takeRead 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

Short-term tolerability is good and the EMA lists most adverse effects at frequencies between 1 and 10 per 1,000, including irritability, restlessness, abnormal dreams, headache, dizziness and daytime somnolence. Doses well above physiological leave melatonin circulating into the morning, which produces grogginess and, in principle, works against the circadian correction being sought. Melatonin is metabolised by CYP1A2, so fluvoxamine markedly raises exposure and smoking lowers it. Long-term safety in children, including any effect on pubertal timing, has not been established by adequate trials, which matters given how widely it is now given to them. In 2020 melatonin became the substance most frequently ingested by children reported to US poison control centres.

Nobody counted how many people took this and were fine, so this cannot be turned into a rate.

Where this came from

Reports sent to a regulator

  • 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.

Melatonin appears in spontaneous reports to regulators. Across the 10 most-reported reaction terms, 1193 reaction mentions were counted. One report can name several reactions.

The recorded terms (10)
  • somnolence — 255 reaction mentions
  • coma — 170 reaction mentions
  • gastrooesophageal reflux disease — 168 reaction mentions
  • pneumonia aspiration — 158 reaction mentions
  • fatigue — 143 reaction mentions
  • tachycardia — 65 reaction mentions
  • suicide attempt — 62 reaction mentions
  • depressed level of consciousness — 59 reaction mentions
  • hypotension — 57 reaction mentions
  • confusional state — 56 reaction mentions
  • open-targets-adr · recorded 2026-06-24 · 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 unclearRead 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 tablet, capsule, gummy, liquid or spray; prolonged-release tablet as an EU prescription medicine

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

In the European Union, the United Kingdom, Australia, Canada and Japan the same molecule is a medicine requiring a prescription or pharmacist supply. Immediate-release and prolonged-release products are pharmacokinetically different interventions and their trial evidence is not interchangeable. Gummy formats are the fastest-growing and the worst-characterised: they are the format at the centre of both the content-accuracy failure and the paediatric ingestion epidemic.

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 which forms are sold and how they compare.

No source is stored against this line.

What is recorded as being sold

  • 60 products list this as an active ingredient in the United States drug directory. 16 of them contain it and nothing else.

    FDA National Drug Code directory · 17089-233 · read 2026-08-29

  • They are sold as liquid, pellet, powder, solution/ drops, spray and tablet, taken oral.

    FDA National Drug Code directory · 17089-233 · read 2026-08-29

  • 50 published labels name it as an active ingredient. 6 of them describe this substance alone, which is where its own label text on this page comes from.

    US prescribing information · 8b6077c2-ecab-441a-8196-fcf736643fc6 · read 2026-08-29

  • Those labels are classed as human otc drug.

    US prescribing information · 8b6077c2-ecab-441a-8196-fcf736643fc6 · read 2026-08-29

  • 1804 marketed supplement labels list this ingredient, classed as non-nutrient/non-botanical, other combinations and hormone.

    NIH Dietary Supplement Label Database · 216782 · read 2026-08-29

  • Those labels carry all other and structure/function claims. A claim of that kind is written by the manufacturer and is not assessed by any regulator, so its presence says nothing about whether it is true.

    NIH Dietary Supplement Label Database · 216782 · 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 takeRead from sources, not yet reviewed

What you could measure

This one is decided with a clinician, so this section holds questions to ask rather than a plan to run.

A single-person plan is offered only as a structure for observing yourself. It never calculates an amount to take, and it cannot prove cause.

Questions worth asking

  • Which of the trials of Melatonin studied people like me?
  • What was measured, and for how long?
  • Was the result a laboratory value or a health outcome?
  • What would we watch for, and when would we stop?

Tracking can show whether something changed for you. It cannot show what caused it.

RNAWiki records evidence. It does not say whether this substance is right for you.

What is missing or unclearRead 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 melatonin is a sedative — it is a circadian signal, and the pooled hypnotic effect is minutes

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 a larger dose is a better dose, when 0.3 mg sufficed and 3.0 mg overshot into the next morning

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 over-the-counter availability in the US implies a broad evidence-supported indication, when the EU authorisation is restricted to short-term use in people 55 and over

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 a labelled dose is the dose received, which is false in 88% of the gummy products tested

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 unclearRead from sources, not yet reviewed

What nobody knows yet

Open questions, each with why it is open and what would close it.

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 Melatonin 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 peopleRead 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.

Seven minutes faster to sleep, eight minutes longer asleep
In plain words
Across nineteen randomised trials in 1,683 people, melatonin cut the time to fall asleep by about seven minutes and added about eight minutes of total sleep.
What was measured
Weighted mean difference in sleep onset latency and total sleep time, in minutes, versus placebo
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Ferracioli-Oda and colleagues pooled 19 randomised placebo-controlled trials in 1,683 subjects with primary sleep disorders. Melatonin reduced sleep onset latency by a weighted mean difference of 7.06 minutes (95% CI 4.37 to 9.75, Z = 5.15, P < 0.001) and increased total sleep time by 8.25 minutes (95% CI 1.74 to 14.75, Z = 2.48, P = 0.013). Overall sleep quality improved with a standardised mean difference of 0.22 (95% CI 0.12 to 0.32, P < 0.001). Meta-regression found longer trials and higher doses produced larger effects on latency and total sleep time, but no dose or duration effect on sleep quality. The authors stated plainly that the absolute benefit is smaller than that of other pharmacological treatments for insomnia, while noting the effect did not appear to dissipate with continued use — which is a genuine advantage over hypnotics that lose effect. The earlier Brzezinski meta-analysis of 17 studies in 284 subjects found the same picture at a smaller scale: sleep onset latency down 4.0 minutes (95% CI 2.5 to 5.4), sleep efficiency up 2.2% (95% CI 0.2 to 4.2), total sleep duration up 12.8 minutes (95% CI 2.9 to 22.8).
Source
Ferracioli-Oda E, Qawasmi A, Bloch MH. PLoS One 2013;8:e63773; Brzezinski A et al. Sleep Med Rev 2005;9:41-50
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
verified
Review state
Written into the record, not signed off as a reviewed claim
Label accuracy: 74% to 347% of the stated dose, and one gummy with none at all
In plain words
Researchers bought 25 melatonin gummy products in the US and measured what was actually in them. Only three matched the label within ten percent. One contained no melatonin.
What was measured
Measured melatonin content as a percentage of the labelled quantity, across commercial products
Effect estimate
No reviewed effect estimate exists for this record.
Limits
This entry records a failure.
From the source
Cohen and colleagues analysed 25 melatonin gummy brands sold in the United States. The actual quantity of melatonin ranged from 74% to 347% of the labelled quantity. Only three of the 25 (12%) contained melatonin within plus or minus 10% of the declared amount. One product contained no detectable melatonin at all but did contain 31.3 mg of CBD. Among the five products containing CBD, CBD content was accurate — 104% to 118% of label — which makes the melatonin failure harder to attribute to general analytical difficulty. Erland and Saxena had found the same problem earlier in 31 supplements: melatonin content ranged from -83% to +478% of label, lot-to-lot variation within a single product reached 465%, more than 71% of supplements missed their label by more than 10%, and serotonin was identified in eight of them at 1 to 75 micrograms. This is the defining fact about the retail category, and it means a person taking "5 mg" may be taking anywhere from under 1 mg to over 17 mg.
Source
Cohen PA et al. JAMA 2023;329:1401-1402; Erland LAE, Saxena PK. J Clin Sleep Med 2017;13:275-281
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
caution
Review state
Written into the record, not signed off as a reviewed claim
The physiological dose worked; the pharmacological dose worked and overshot
In plain words
A dose-ranging study found that a small dose matching the body's own night-time level restored sleep efficiency. A ten-times-larger dose also worked, but dropped body temperature and left melatonin circulating into the next day.
What was measured
Polysomnographic sleep efficiency and plasma melatonin profile across 0.1, 0.3 and 3.0 mg doses
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Zhdanova and colleagues ran a double-blind placebo-controlled crossover in 30 subjects over 50 — 15 with actigraphically confirmed reduced sleep efficiency and 15 normal sleepers — giving placebo and 0.1, 0.3 and 3.0 mg melatonin 30 minutes before bed for a week each, with polysomnography on the last three nights of each period. The physiological dose of 0.3 mg restored sleep efficiency (P < 0.0001), acting principally in the middle third of the night, and raised plasma melatonin to the normal nocturnal range (P < 0.0008). The pharmacological 3.0 mg dose also improved sleep, but induced hypothermia and caused plasma melatonin to remain elevated into the daylight hours. The 0.1 mg dose also improved sleep. Crucially, control subjects with equally low melatonin levels showed no sleep effect at any dose. Retail products in the US are commonly sold at 3, 5 and 10 mg, which is ten to thirty times the dose that this study showed sufficed, and the surplus does not simply vanish: it keeps signalling night into the following morning, which is the opposite of what a circadian intervention should do.
Source
Zhdanova IV et al. J Clin Endocrinol Metab 2001;86:4727-4730
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
verified
Review state
Written into the record, not signed off as a reviewed claim
Jet lag is the strong indication, and it is a different mechanism
In plain words
For jet lag — a genuine mismatch between the body clock and local time — a Cochrane review of ten randomised trials found melatonin remarkably effective. This is the use with the best evidence and the least marketing.
What was measured
Subjective jet lag ratings and related components after eastward and westward transmeridian flight
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
Herxheimer and Petrie identified ten randomised trials in airline passengers, staff and military personnel, all comparing melatonin with placebo and one additionally with the hypnotic zolpidem. Jet lag is the one condition where the pharmacology and the pathology match exactly: the problem is that the internal clock is set to the departure time zone, and melatonin is the signal that moves it. The evidence is coherent for eastward travel across several time zones, where the required phase advance is the harder direction. Adverse event reports were searched systematically outside the randomised trials as well, in Side Effects of Drugs, Reactions Weekly, MEDLINE, and the WHO Uppsala Monitoring Centre and FDA adverse reaction databases. The contrast with the insomnia literature is the point of this audit: the same molecule has a strong indication with a matching mechanism and a weak indication without one, and the weak one is what the aisle sells.
Source
Herxheimer A, Petrie KJ. Cochrane Database Syst Rev 2002;2:CD001520
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
verified
Review state
Written into the record, not signed off as a reviewed claim
Paediatric ingestions rose 530 percent, with two deaths
In plain words
As melatonin gummies spread, so did children eating them. Over ten years US poison centres logged more than a quarter of a million paediatric melatonin ingestions, five children needed ventilators and two died.
What was measured
Annual paediatric melatonin ingestions reported to US poison control centres, and associated outcomes
Effect estimate
No reviewed effect estimate exists for this record.
Limits
This entry records a failure.
From the source
Lelak and colleagues analysed the American Association of Poison Control Centers National Poison Data System for isolated melatonin ingestions in people aged 19 or under from 2012 to 2021. There were 260,435 paediatric melatonin ingestions over the decade and the annual number rose 530%. Melatonin accounted for 4.9% of all paediatric ingestions reported in 2021 against 0.6% in 2012, and in 2020 it became the substance most frequently ingested by children reported to poison centres. Hospitalisations and serious outcomes increased, driven mainly by unintentional ingestion in children aged five or under. Five children required mechanical ventilation and two died. US sales rose from 285 million dollars in 2016 to 821 million in 2020 over the same period. A sweet, brightly coloured, unregulated product with no child-resistant requirement and no reliable content standard is the direct explanation, and the content variability audit above compounds it: a child eating a handful of gummies may be receiving several times more melatonin per gummy than the label implies.
Source
Lelak K et al. MMWR Morb Mortal Wkly Rep 2022;71:725-729
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
verified
Review state
Written into the record, not signed off as a reviewed claim
The regulated version exists, and its authorised claim is much narrower
In plain words
In Europe melatonin is a prescription drug. Regulators approved it only for short-term use in people over 55, and the trial result behind that approval was 32 percent responding against 19 percent on placebo.
What was measured
Proportion reporting significant improvement in sleep quality and next-day functioning at three weeks
Effect estimate
No reviewed effect estimate exists for this record.
Limits
See the technical detail.
From the source
The EMA authorised Circadin, prolonged-release melatonin 2 mg, on 29 June 2007 under EMEA/H/C/000695, as monotherapy for the short-term treatment of primary insomnia characterised by poor quality of sleep in patients aged 55 or over, available only on prescription and for up to 13 weeks. Across three main studies in 681 patients, 32% of Circadin patients (86 of 265) reported significant improvement in sleep quality and next-day functioning at three weeks against 19% on placebo (51 of 272). Everything in that sentence is a restriction the US supplement carries none of: a specific formulation, a specific dose, an age floor, a duration cap and a prescription requirement. The inference to audit is the reverse of the usual one — American consumers routinely treat the availability of melatonin without a prescription as evidence that it is mild and broadly indicated, when the jurisdiction that assessed it concluded the opposite about scope while agreeing it is safe enough to prescribe.
Source
European Medicines Agency, Circadin EPAR summary, marketing authorisation issued 29 June 2007
Role in the trial
Not matched to a registered study
Identity check
no open identity hold
Audit mark
verified
Review state
Written into the record, not signed off as a reviewed claim

Where else this substance is registered

CAS registry number
73-31-4
PubChem compound
896
RxNorm concept
6711

Checks this page had to pass

  • Passed

    Identity resolved

    no open identity hold

  • Passed

    No unresolved merge across substance families

    no quarantine open

  • Passed

    Every public sentence names a source

    The opening statement carries the origin: Written into the record, not signed off.

  • Not passed

    Trial roles classified for highlighted evidence

    No registered study is classified as testing this substance.

  • Passed

    No internal keys in reader text

    enforced by the copy-contract test over the rendered page

  • Passed

    Safety mode resolved

    The identity record classes it as a supplement ingredient; no medicines register records an approval.

  • Passed

    Canonical metadata present

    slug and display name present

What is missing or unclearRead from sources, not yet reviewed

How this medicine reached us

Kept near the foot of the page. A historical event moves up only when it changes something about this substance today.

What the approval register records

  • The earliest marketing start date recorded for a listed product is 19840815.

    FDA National Drug Code directory · 17089-233 · read 2026-08-29

What is missing or unclearRead from sources, not yet reviewed

What to learn next

Ordered by what would most change how you read this page, starting with what is easiest to misunderstand.

This order is fixed in code and does not count clicks or time on the page.

What is not here

3 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 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.

Melatonin genuinely shortens sleep onset, by about seven minutes across 19 trials and 1,683 people, and genuinely shifts circadian phase, which is a different and better-supported claim — but the typical retail dose is roughly ten times the physiological one, and in 25 US gummy brands the measured content ran from 74% to 347% of what the label said, with one containing no melatonin at all.

Recorded evidence blocks (14)

What did Melatonin's largest trial (10000 people) and its longest (33 years) measure?

10000 people in Melatonin's largest registered study, 33 years in its longest registered window, measuring Lung Cancer Recurrence or Mortality - 2 Years. ClinicalTrials.gov · 2026-09-01

126 phase2, 113 na, 79 phase3, 49 phase4, 41 phase1, 20 early phase1, 4 na or unstated; NCT00262470; 2029-12. Last human test completed 2026, NCT06382610.

Interpretation These counts include studies where Melatonin was a comparison treatment, a background treatment or an exposure in an observational study, and the longest window may be a planned end date. Trial roles have not yet been classified for this record.

Show the evidence
  • phase2
    126
  • na
    113
  • phase3
    79
  • phase4
    49
  • phase1
    41
  • early phase1
    20
2 more recorded rows
  • na or unstated
    4
  • Last recorded human test NCT06382610
    2026-07-31

recorded 2026-09-01 · last checked 2026-09-04

From C. elegans to human: where has Melatonin shown lifespan?

C. elegans: lifespan, Drosophila: lifespan, NHP: lifespan, mouse: mechanism-only, rat: lifespan, dog: mechanism-only and human: lifespan (384): the rungs where Melatonin has a recorded finding. Europe PMC and ClinicalTrials.gov · organism ladder · 2026-09-01

Lung Cancer Recurrence or Mortality - 2 Years — the recorded outcome words.

Yeast C. elegans lifespanDrosophila lifespanMouse mechanism-onlyRat lifespanDog mechanism-onlyNon-human primate lifespanHuman lifespan
Show the evidence
  • C. elegans
    lifespan
  • Drosophila
    lifespan
  • NHP
    lifespan
  • mouse
    mechanism-only
  • rat
    lifespan
  • dog
    mechanism-only
1 more recorded row
  • human NCT00668707
    lifespan; Lung Cancer Recurrence or Mortality - 2 Years; 384

recorded 2026-09-01 · last checked 2026-09-04

42 of Melatonin's trials stopped: safety, futility/efficacy, accrual/recruitment, funding/business, other?

safety (1), futility/efficacy (2), accrual/recruitment (11), funding/business (5) and other (23): Melatonin's stop wording, clustered. ClinicalTrials.gov · 2026-09-01

"Terminated due to low accrual."; 42 of 384 registered studies

Show the evidence

Trial

  • NCT00506064
    terminated; "Terminated due to low accrual."
  • NCT00625742
    terminated; "Low Accrual"
  • NCT00688935
    terminated; "Unique provision in the American Recovery and Reinvestment Act prevented approval of second year no-cost-extension in which completion of analyses were planned."
  • NCT00691444
    terminated; "Unique provision in the American Recovery and Reinvestment Act prevented approval of second year no-cost-extension in which completion of analyses were planned."
  • NCT00691574
    terminated; "Unique provision in the American Recovery and Reinvestment Act prevented approval of second year no-cost-extension in which completion of analyses were planned."
  • NCT00692094
    terminated; "Unique provision in the American Recovery and Reinvestment Act prevented approval of second year no-cost-extension in which completion of analyses were planned."
14 further recorded trials
  • NCT00795236
    terminated; "Unique provision in the American Recovery and Reinvestment Act prevented approval of second year no-cost-extension in which completion of analyses were planned."
  • NCT00869869
    withdrawn; "No subjects were enrolled in this study. Funding ran out."
  • NCT00911053
    terminated; "Unique provision in the American Recovery and Reinvestment Act prevented approval of second year no-cost-extension in which completion of analyses were planned."
  • NCT01033565
    terminated; "Unsuccessful in recruiting appropriate subjects."
  • NCT01355523
    terminated; "Inclusion rate not as expected. Not financially possible to involve other centres."
  • NCT01370486
    withdrawn; "The study did not received the approbation from Swissmedic. Therefore, the recruitment of participants never started."
  • NCT01598259
    terminated; "lack or enrollment, funding depletion"
  • NCT01904786
    withdrawn; "Lack of enrollment of suitable candidates"
  • NCT02099331
    withdrawn; "Lack of faculty staffing"
  • NCT02190838
    terminated; "Preliminary terminated due to inefficacy"
  • NCT02282241
    withdrawn; "Project never began"
  • NCT02319265
    withdrawn; "Study registered elsewhere and is not covered by FDA"
  • NCT02332928
    terminated; "Lack of efficacy"
  • NCT02333149
    withdrawn; "Issues surrounding the current COVID-19 pandemic."

recorded 2026-09-01 · last checked 2026-09-04

Human studies of Melatonin used Melatonin 0.4 mg — over how long?

Human studies of Melatonin used "Melatonin 0.4 mg". ClinicalTrials.gov · 2026-09-01

20 recorded entries; human; also "Melatonin 4.0 mg", "melatonin 0.5 mg", "Life Extension Melatonin 5 mg"

Show the evidence

human

  • NCT00230737
    Melatonin 0.4 mg
  • NCT00230737
    Melatonin 4.0 mg
  • NCT00288262
    melatonin 0.5 mg
  • NCT00387179
    Life Extension Melatonin 5 mg
  • NCT00470821
    Oral melatonin 3mg BID
  • NCT00470821
    MELATONIN 3 mg
14 more recorded rows
  • human NCT00749814
    Circadin (melatonin 2 mg)
  • human NCT00869128
    Prolonged-release melatonin (2mg)
  • human NCT01126294
    5 mg melatonin
  • human NCT01126294
    10 mg melatonin
  • human NCT01280734
    Circadin (R) 2 mg
  • human NCT01572805
    melatonin 3mg
  • human NCT01572805
    melatonin 6mg
  • human NCT01706627
    10 mg Melatonin
  • human NCT01706627
    20 mg Melatonin
  • human NCT01805089
    Melatonin 3 mg
  • human NCT01811160
    Melatonin 5mg capsules were administered at 20:00hrs during the follow up period.
  • human NCT01858909
    Liquid 1 mg/mL Melatonin
  • human NCT01903681
    Circadin 2 mg
  • human NCT01903681
    Circadin 10 mg

recorded 2026-09-01 · last checked 2026-09-04

Melatonin's half-life is mean 53.7 minutes — which schedules were studied?

mean 53.7 minutes, the half-life Melatonin's label states. openfda-label · 2026-08-27

Show the evidence
  • half life
    mean 53.7 minutes minutes; Mean t 1/2 elimination was 53.7 (7.0) min. Median absolute bioavailability was 2.5 (1.7-4.7) %.

recorded 2026-08-27 · last checked 2026-09-04

Could one person measure Melatonin's effect on improvement in jet lag symptoms?

Improvement in jet lag symptoms: measured in Melatonin's trials.

Interpretation improvement in jet lag symptoms is the recorded endpoint.

Show the evidence

biomarkers

  • improvement in jet lag symptoms; 2026-09-01
  • fatigue; 2026-09-01
  • sleep quality; 2026-09-01
  • increase in heart rate standing; 2026-09-01
  • luteinizing hormone; 2026-09-01
  • gain in lean body mass; 2026-09-01
14 more recorded rows
  • biomarkers
    infarct size; 2026-09-01
  • biomarkers
    sleep efficiency; 2026-09-01
  • biomarkers
    migraine attack frequency; 2026-09-01
  • biomarkers
    sleep duration; 2026-09-01
  • biomarkers
    total sleep time; 2026-09-01
  • biomarkers
    clinical global impression improvement; 2026-09-01
  • biomarkers
    pain; 2026-09-01
  • biomarkers
    anxiety; 2026-09-01
  • biomarkers
    incidence of postoperative delirium; 2026-09-01
  • biomarkers
    relapses; 2026-09-01
  • biomarkers
    edss; 2026-09-01
  • biomarkers
    intention to treat depression at one in the study period; 2026-09-01
  • biomarkers
    headache days from baseline to month 3 after treatment; 2026-09-01
  • biomarkers
    abnormal involuntary movement scale; 2026-09-01
  • half life
    2026-09-04; halfLife; minutes; mean 53.7 minutes; 2026-08-27
  • human trials at or under30
    106
  • smallest human trial
    0; NCT00869869; PHASE2; the smallest recorded human enrolment at or below 30; the registry states no direction of its result; WITHDRAWN

Which of abnormal involuntary movement scale, adhd symptoms improvement and anxiety did Melatonin's trials measure?

abnormal involuntary movement scale, adhd symptoms improvement and anxiety lead 40 outcome terms across Melatonin's trials. ClinicalTrials.gov · 2026-09-01

Interpretation increase in heart rate standing, luteinizing hormone, gain in lean body mass, infarct size, sleep efficiency and migraine attack frequency follow.

Show the evidence
  • improvement in jet lag symptoms
    1
  • fatigue
    1
  • sleep quality
    1
  • increase in heart rate standing
    1
  • luteinizing hormone
    1
  • gain in lean body mass
    1
14 more recorded rows
  • infarct size
    1
  • sleep efficiency
    1
  • migraine attack frequency
    1
  • sleep duration
    1
  • total sleep time
    1
  • clinical global impression improvement
    1
  • pain
    1
  • anxiety
    1
  • incidence of postoperative delirium
    1
  • relapses
    1
  • edss
    1
  • intention to treat depression at one in the study period
    1
  • headache days from baseline to month 3 after treatment
    1
  • abnormal involuntary movement scale
    1

recorded 2026-09-01 · last checked 2026-09-04

Which of Melatonin's 64 ongoing trials reports first?

64 registered trials of Melatonin are open; earliest completion 2025-06-01. ClinicalTrials.gov · 2026-09-01

Increase in heart rate with standing; Pittsburgh Sleep Quality Index (PSQI) Score Change; latest 2031-01-01

Show the evidence

Trial

  • NCT00262470
    "Treatment of Orthostatic Intolerance"; n 150; "Increase in heart rate with standing"; 2029-12
  • NCT01628029
    "Cognitive Behavioral Therapy and Multimodal Therapy in Treating Sleep Disturbance in Patients With Cancer"; n 68; "Pittsburgh Sleep Quality Index (PSQI) Score Change"; 2028-12-31
  • NCT02621944
    "Melatonin as a Neuroprotective Therapy in Neonates With HIE Undergoing Hypothermia"; n 70; "To identify the maximum tolerated dose of Melatonin"; 2027-03
  • NCT03438526
    "The Basel BOMP-AID Randomized Trial"; n 190; "Duration of hypoactive delirium"; 2027-12
  • NCT03954899
    "Disease Modifying Potential of 5mg of Melatonin on Cognition and Brain Health in Aging"; n 230; "Episodic memory"; 2025-11
  • NCT04233112
    "Melatonin and Osteogenic Loading on Osteopenia"; n 40; "Bone mineral density"; 2025-09-01
14 further recorded trials
  • NCT04247646
    "SLeep and OPioid UsE in Patients Undergoing Total Knee Arthroplasty"; n 120; "Opioid use"; 2028-12-31
  • NCT04547439
    "Sleep, Diabetic Retinopathy and Melatonin"; n 42; "Sleep pattern"; 2026-06
  • NCT04588233
    "Melatonin Adolescent Research Study"; n 80; "Change in Objective Sleep Duration During Melatonin Administration"; 2027-05
  • NCT04631341
    "Melatonin and Risk Of Cardiovascular Events And Malignant Tumors In The Elderly"; n 10000; "Total cancer and cardiovascular disease incidence"; 2026-12-31
  • NCT04831398
    "The Effects of Acute Melatonin Supplementation on Cardiovascular Responses to Sympathetic Activation"; n 100; "Muscle Tissue Oxygenation"; 2026-12
  • NCT05084196
    "Melatonin for Prevention of Kidney Injury"; n 300; "Acute kidney injury"; 2027-12-31
  • NCT05358834
    "Testing Effects of Melatonin on Uterine Contractions in Women"; n 120; "Daytime: Total number of uterine contractions"; 2027-06-30
  • NCT05474846
    "Combination Therapy for Treatment of Sleep Disturbance in Patients With Advanced Cancer"; n 188; "Pittsburgh Sleep Quality Index (PSQI) questionnaires"; 2027-02-28
  • NCT05502900
    "Adjuvant Melatonin for Uveal Melanoma"; n 100; "Number of patients that develop metastases in Melatonin vs. Control arm, evaluated as relative risk (RR)."; 2031-01-01
  • NCT05541276
    "MELAtonin for Prevention of Postoperative Agitation and Emergence Delirium in Children"; n 676; "Incidence of emergence agitation"; 2027-04-01
  • NCT05651347
    "Antenatal Melatonin Supplementation for Neuroprotection in Fetal Growth Restriction"; n 336; "Neurodevelopmental performance at 2 years of life among survivors of early onset FGR."; 2027-04-30
  • NCT05701969
    "Effect of Melatonin on Sleep Patterns of Resident Trainees During Night Float Shift"; n 50; "Total Sleep Time (TST)"; 2028-06-30
  • NCT05713877
    "Melatonin for Treatment of Delirium in Critically Ill Adult Patients"; n 30; "Feasibility: Enrollment rate"; 2026-12-30
  • NCT05716906
    "Melatonin and Sleep Spindles in Autism"; n 30; "Change in sleep spindle density"; 2027-01-01

recorded 2026-09-01 · last checked 2026-09-04

Which running trial of Melatonin could settle lifespan?

NCT07305350 measures Neonate survival rate, reading out 2026-05-10.

3 open trials; n 110; "EFFICACY OF MELATONIN IN MANAGEMENT OF HYPOXIC ISCHEMIC ENCEPHALOPATHY (HIE) IN NEONATES"

Show the evidence

Trial

  • NCT07305350
    "EFFICACY OF MELATONIN IN MANAGEMENT OF HYPOXIC ISCHEMIC ENCEPHALOPATHY (HIE) IN NEONATES"; n 110; "Neonate survival rate"; 2026-05-10
  • NCT07307677
    "Melatonin & Metformin on Clinical & Biochemical Parameters in Insulin Resistant PCOS Compared to Metformin"; n 60; "Change in Homeostatic Model Assessment of Insulin Resistance (HOMA-IR)"; 2026-08-10
  • NCT07721324
    "Effect of Melatonin Administration on Systemic Lupus Erythematosus Patients"; n 64; "Serum Interleukin- 6 (IL-6)"; 2026-11-21

Which 118 trials of Melatonin posted no result?

Posted no result
118 of 118 completed trials
Registrations
NCT00816673, NCT00113906, NCT00404456, NCT00972075, NCT00097474 and NCT00873379, and 112 more
Completion dates
oldest 1997-09; newest 2024-09-01
Show the evidence

Trial

  • NCT00816673
    1997-09
  • NCT00113906
    2006-08
  • NCT00404456
    2007-07
  • NCT00972075
    2007-10
  • NCT00097474
    2007-11-14
  • NCT00873379
    2008-03
14 further recorded trials
  • NCT00315926
    2008-07
  • NCT00849511
    2009-10
  • NCT00675181
    2010-01
  • NCT00470821
    2010-05
  • NCT01200641
    2011-01
  • NCT01087359
    2011-02
  • NCT01280734
    2011-05
  • NCT01391390
    2011-05
  • NCT00825591
    2011-09
  • NCT01811160
    2011-11
  • NCT01115127
    2011-12
  • NCT02107079
    2012-01
  • NCT01706627
    2012-06
  • NCT01572805
    2012-10

At the median, Melatonin's trials enrolled 55 people — anything larger?

Median enrolment
55
Largest enrolment
10000
Registered trials counted
381

What do 1193 spontaneous reports say about Melatonin — 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.

Melatonin appears in spontaneous reports to regulators. Across the 10 most-reported reaction terms, 1193 reaction mentions were counted: somnolence 255; coma 170; gastrooesophageal reflux disease 168; pneumonia aspiration 158. open-targets-adr · CHEMBL45 · 2026-06-24

Show the evidence
  • somnolence
    255
  • coma
    170
  • gastrooesophageal reflux disease
    168
  • pneumonia aspiration
    158
  • fatigue
    143
  • tachycardia
    65
4 more recorded rows
  • suicide attempt
    62
  • depressed level of consciousness
    59
  • hypotension
    57
  • confusional state
    56

recorded 2026-06-24 · last checked 2026-09-04

Was Melatonin studied with fasting and exercise?

fasting and exercise are named in Melatonin's label sentences: "This systematic review and dose-response meta-analysis of randomized controlled trials (RCTs) evaluated the impacts of melatonin supplementation on CMRFs, including anthropometric, lipid, glycemic, inflammatory, oxidative, and liver function parameters. <b>Methods</b>: A systematic search across…" openfda-label+europepmc · 2026-02-28

2 recorded statements; fasting, exercise

Show the evidence
  • fasting
    This systematic review and dose-response meta-analysis of randomized controlled trials (RCTs) evaluated the impacts of melatonin supplementation on CMRFs, including anthropometric, lipid, glycemic, inflammatory, oxidative, and liver function parameters. <b>Methods</b>: A systematic search across multiple databases retrieved 63 eligible RCTs published up to October 2025. <b>Results</b>: This…
  • exercise
    <b>Background/Objectives</b>: This study examined the acute effects of different doses of melatonin on performance, physiological, and psychophysiological responses during individualized exhaustive cycling exercise. <b>Methods</b>: Fifteen physically active but cycling-inexperienced men (18-35 years) completed a double-blind, randomized, placebo-controlled, crossover protocol.

recorded 2026-02-28 · last checked 2026-09-04

What is recorded about Melatonin and sirtuin?

"Melatonin effectively mitigates fluoride-induced neurotoxicity and cognitive dysfunction in Wistar rats by modulating oxidative stress, neuroinflammation, apoptosis, and SIRT1 signaling." — where Melatonin and sirtuin appear together. Europe PMC · pathway abstract search · 2026-07-29

sirtuin, autophagy, mTOR, AMPK, senolytic, NAD+; PMID 42494681, 41456437, 41822807, 42097527

Show the evidence
  • sirtuin PMID 42494681
    "Melatonin effectively mitigates fluoride-induced neurotoxicity and cognitive dysfunction in Wistar rats by modulating oxidative stress, neuroinflammation, apoptosis, and SIRT1 signaling."
  • autophagy PMID 41456437
    "ER stress inhibitor 4‑phenylbutyric acid attenuated melatonin‑induced autophagy, linking ER stress relief to autophagic activation."
  • mTOR PMID 41456437
    "Mechanistically, melatonin upregulated p21‑activated kinase 2 (Pak2), which suppressed mTOR phosphorylation and activated unc‑51‑like kinase 1, thereby modulating the AMP‑activated protein kinase (AMPK) pathway."

AMPK

  • PMID 41456437
    "Mechanistically, melatonin upregulated p21‑activated kinase 2 (Pak2), which suppressed mTOR phosphorylation and activated unc‑51‑like kinase 1, thereby modulating the AMP‑activated protein kinase (AMPK) pathway."
  • PMID 41456437
    "Pak2 overexpression amplified melatonin's ER stress‑alleviating effects, whereas Pak2 knockdown or AMPK inhibition diminished its efficacy."

sirtuin

  • PMID 41822807
    "Furthermore, siRNA targeting melatonin receptor 2 (MT2) attenuated melatonin-induced SIRT1 upregulation, ETS1 deacetylation, and pyroptosis inhibition."
  • PMID 41822807
    "Our findings indicate that melatonin alleviates LPS-induced pyroptosis in alveolar epithelial cells through the MT2/SIRT1/ETS1/NLRP3 signaling pathway."

mTOR

  • PMID 42097527
    "The impact of melatonin on hypoxia-reoxygenation (H/R)-treated wild-type and SIRT7-knockdown human umbilical vein endothelial cells (HUVECs) was evaluated, along with the modulation of SIRT7 expression and the Protein kinase B/mammalian target of rapamycin (AKT/mTOR) signaling pathway."
  • PMID 42097527
    "Conversely, melatonin administration activated the AKT/mTOR signaling pathway."
  • senolytic PMID 42392409
    "Pharmacological interventions such as quercetin (a p38 MAPK inhibitor), melatonin (an Nrf2 activator), and senolytic agents illustrate the potential to disrupt the senescence-PCD axis."
  • AMPK PMID 42526786
    "Melatonin (MEL) and Metformin (MET), an effect associated through the AMP-activated protein kinase/Sirtuin 3 (AMPK/SIRT3) signaling pathway."
  • NAD+ PMID 41485639
    "Furthermore, it is found that melatonin suppressed NAMPT expression via inhibition of YAP1."

autophagy

  • PMID 40561830
    "Moreover, Autophagy inhibits pyroptosis, which is affected by melatonin via up-regulation of SIRT1."
  • PMID 40561830
    "However, the role of melatonin in regulating autophagy and pyroptosis through the SIRT1/p53 pathway in lessening IR-induced AKI is yet to be elucidated."
  • NAD+
    "Our previous studies showed that melatonin alleviated mitochondrial dysfunction by upregulating SIRT1 (NAD-dependent deacetylase sirtuin-1) expression."
  • senolytic PMID 42378907
    "We critically evaluate the preclinical efficacy of senolytics (eg, dasatinib + quercetin, navitoclax, fisetin), and senomorphics (eg, rapamycin, metformin, melatonin, NLRP3 inhibitors) in preserving ovarian reserve, mitigating SASP-driven inflammation and fibrosis, and extending reproductive lifespan."
  • NAD+ PMID 41824483
    "Mitochondria-directed antioxidants such as melatonin and coenzyme Q10, NAD⁺ boosters and sirtuin activators, red and near-infrared photobiomodulation, and NRF2-based redox reprogramming each enhance mitochondrial homeostasis while improving collagen synthesis, pigmentation balance, and re-epithelialization."

recorded 2026-07-29 · last checked 2026-09-04

Where it is registered
Identifiers, relations and other names

The exact record

ChEMBL id
CHEMBL45
PubChem CID
896
CAS number
73-31-4
RxCUI
6711
InChIKey
DRLFMBDRBRZALE-UHFFFAOYSA-N
Also called
5-methoxy n-acetyl-tryptamine, Melatol, Melatonine, Melovine, Regulin, Tartrol, exogenous melatonin, ki1001, melatonin cr, mlt, mt, n-acetyl-5-methoxytryptamine
Development code
BCI-049, J5.258B, NSC-113928, NSC-302012, NSC-56423
Trade name
Circadin, General nutrit, Health aid, Heidadouppi, Icenia, Life ext, Melapure, Melatonin neurim, Natrol, Nature's blend, Natures bounty, Quality health
Sources (11)

Sources

  • ClinicalTrials.gov clinicaltrials.gov ·
  • ClinicalTrials.gov ClinicalTrials.gov API v2 snapshot 2026-09-01T09:00:05 ·
  • this record's own fields 2,3,5 ·
  • Europe PMC dose-response search ·
  • Europe PMC pathway abstract search ·
  • Europe PMC search ·
5 more sources

ChEMBL ATC CC BY-SA · ClinicalTrials.gov — US Government work · Europe PMC — metadata only, under the recorded legal gate · Open Targets 26.06 — CC0 · derived from this page's own recorded fields; no external licence · mixed register set; per-register licences in docs/specs/corpus-20k-sources.md · openFDA / DailyMed — US Government work

How these records are assembled · Which registers were checked

Index-quality checks
  • identity passed: no open identity hold
  • required summary fields resolved: 5 required field(s) not terminal: Why people use it, Best-supported result, Most important common problem, Biggest unanswered question, Human evidence
  • public claims reviewed: 0 reviewed claim(s); drafts are never rendered
  • source coverage passed: 11 source rows
  • no critical contamination: no quarantine open
  • canonical metadata passed: slug and display name present
  • no raw internal fields: enforced by the copy-contract test over the rendered page

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