Sleep
Melatoninand Total sleep time
Both sources here measured higher total sleep time.
How sure anyone can be
Low certainty, level 2 of 4Further research is likely to change this.
The most certain of the two findings here; each record carries its own.
The numbers reported
One source’s range, drawn against its own line of no difference and scaled to its own numbers.
8.112.4 minutes16.7
This range stays on one side of the no-difference line.
Two sources, newest first
What we read is the published abstract, not the full paper, so a blank below may still be printed in the paper itself. A fixed rule worked this out from the source’s own fields. Nobody checked this rating by hand.
Systematic review, 2025
Low certainty, level 2 of 4Melatonin for sleep and cognitive outcomes in older adults with cognitive impairment: a meta-analysis of randomised controlled trials.
Age Ageing. 2025;54(11). doi:10.1093/ageing/afaf333. PMID:41240058.
- Number reported
- 12.4 minutes
- Which way it went
- Higher
- Likely range
- 8.1 to 16.7
- Source’s own words
- minutes of total sleep time, mean difference vs placebo
- Who was studied
- Older adult with cognitive impairment
- Compared with
- placebo
- Amount taken
- Not in the abstract
- For how long
- Not in the abstract
- Disagreement between studies
- I2 = 72%
- Kind of record
- Journal article
How this rating was reachedstarts at High, 2 steps down: imprecision and inconsistency
- Starts at High
- Imprecision brought it down to Moderatethe abstract does not state how many participants were pooledNot in the abstract
- Inconsistency brought it down to Lowheterogeneity across pooled studies is high (I² = 72%)Reported in the abstract
- Ends at Low2 steps down.
- Checked, nothing to step it down for
- risk of bias and indirectness
Imprecision stops at the first check that applies; others may apply too.
AI review could not confirm it — an AI agent re-read this finding against the saved source and at least one check failed. The batch record names the check and quotes the sentence that caused the doubt. No person read it.
Systematic review, 2013
Low certainty, level 2 of 4Meta-analysis: melatonin for the treatment of primary sleep disorders.
PLoS One. 2013;8(5):e63773. doi:10.1371/journal.pone.0063773. PMID:23691095.
- Number reported
- 8.25 minutes
- Which way it went
- Higher
- Likely range
- 1.74 to 14.75
- Source’s own words
- minutes of total sleep time, weighted mean difference vs placebo
- Who was studied
- Adult or child with primary sleep disorder
- Compared with
- placebo
- Amount taken
- Not in the abstract
- For how long
- Not in the abstract
- Disagreement between studies
- Not in the abstract
- Kind of record
- Journal article
How this rating was reachedstarts at High, 2 steps down: risk of bias and imprecision
- Starts at High
- Risk of bias brought it down to Moderatethe abstract reports no risk-of-bias or quality appraisal, so study limitations cannot be ruled outNot in the abstract
- Imprecision brought it down to Lowthe abstract does not state how many participants were pooledNot in the abstract
- Ends at Low2 steps down.
- Checked, nothing to step it down for
- indirectness
- Inconsistency
- No disagreement reported, and no count of studies behind it
Imprecision stops at the first check that applies; others may apply too.
AI-reviewed & signed — an AI agent re-read this finding against the saved source and checked that the quote, the numbers, the units and the direction match it. No person read it. The owner authorised the agent to sign the batch with the owner's key, and every build rechecks that signature against these exact bytes.
What is still missing from these readings
- Two do not say how many people took part.
- Amount taken — Not in the abstract.
- For how long — Not in the abstract.
Something nobody wrote down is never a zero and never a guess.
Still to read for Melatonin
Two of the ten things on our list for Melatonin have no reading here yet:
- Body Temperature
- Serum cortisol (morning)
Still to read means nobody here has got to it, not that it was tried and did nothing or that no research exists. A pairing on no list is not a gap: we never set out to read it.
Read next
Melatonin
Eight other questions read for it
Sleep
28 questions read under it
Total sleep time
Three other ingredients read against it
Alphabetical, and by nothing else.
This is a library, not advice. No recommendation, no dose, no diagnosis, no ranking. We never ask about your symptoms, and nothing here is tailored to you.