Mental Health

Sleep Issues

About Sleep Issues — Mental Health.

Difficulty falling asleep, staying asleep, or poor sleep quality. Insomnia affects ~30% of adults.

5studies analysed

2compounds with evidence

Systematic reviewstrongest evidence

Where research is strongest

Add your outcome — free & pseudonymous

Tried something for Sleep Issues? Share how it went — only ever published as part of a group of 10+.

5linked compounds

59linked studies

0published community reports

Results By the numbers Community Research Compounds

Headline results for Sleep Issues.

Figures as the studies reported them.

Colour keyReported a benefitNo clear benefitUnclearPossible harmAmber is for highlights, such as where the most research is. It never means a result was good.

Melatonin

4 of 4 results reported a benefit

2 studies, including a review of trials

Total sleep timeLarge effectmuch better than the comparison group1 review of trials2020 study ↗

No figure given: Overall sleep (reported a benefit).

Also measured alongside: Overall thinking skills (reported a benefit); Tiredness (fatigue) (reported a benefit).

Every result

Glycine

5 of 6 results reported a benefit

3 studies, including a review of trials

Overall sleepReported a benefitLonger-term glycine administration improved Sleep in healthy adults (small studies, high risk of bias) with no comparator reported.1 review of trials · no comparable figure reported2 of 2 results reported a benefit2024 study ↗

Also measured alongside: Daytime sleepiness (unclear); Alertness test performance (reported a benefit); Tiredness (fatigue) (reported a benefit); and 1 more.

Every result

Where the evidence is concentrated.

Published research

Sleep Issues: findings by compound

What this means: Bars count reported findings, not treatment effectiveness or certainty.

One study may report several findings or appear in more than one pairing. Counts do not show the size of an effect. Comparable numerical estimates are not established for this summary.

View the full data table

Published research: reported directions by pairing
Compound and condition	Findings (count)	Studies (count)	Reported results (finding counts)	How sure?
Melatonin	5	2	Benefit: 4; no benefit: 1; harm: 0; unclear: 0; not recorded / unrecognised: 0	Not formally graded
Glycine	6	3	Benefit: 5; no benefit: 0; harm: 0; unclear: 1; not recorded / unrecognised: 0	Not formally graded

Degree of benefit for Sleep

Strongest evidence first.

Published research: Sleep. Study design is not a certainty grade.
Compound	Study designs	Reported findings
MelatoninResearch score 58/100 · Moderate	2 systematic reviews/meta-analyses — 2 studies	4/5 outcomes showed benefit Sleep durationMuch better than the comparison group (large effect)benefit2020 study ↗ Exact figures 1.07 (Hedge's g 1.07 [95% CI 0.49-1.65]) · Follow-up: Not reported · Sample (as reported): Not reported · Recorded unit: Not reported · Sleep Disorders in Children and Adolescents with Autism Spectrum Disorder: Diagnosis, Epidemiology, and Management. · Meta-Analysis · meta-analysis · PMID 32112261 Sleep conditionsReported a benefit — measurement not reportedbenefit2023 study ↗ Exact figures No figures reported · Follow-up: 2 weeks and 12 months · Sample (as reported): Not reported · Recorded unit: Not reported · Clinical efficacy and safety of melatonin supplementation in multiple sclerosis: a systematic review. · Systematic Review · systematic-review · PMID 37429996 Cognitive outcomesReported a benefit — measurement not reportedbenefit2023 study ↗ Exact figures No figures reported · Follow-up: 2 weeks and 12 months · Sample (as reported): Not reported · Recorded unit: Not reported · Clinical efficacy and safety of melatonin supplementation in multiple sclerosis: a systematic review. · Systematic Review · systematic-review · PMID 37429996 FatigueReported a benefit — measurement not reportedbenefit2023 study ↗ Exact figures No figures reported · Follow-up: 2 weeks and 12 months · Sample (as reported): Not reported · Recorded unit: Not reported · Clinical efficacy and safety of melatonin supplementation in multiple sclerosis: a systematic review. · Systematic Review · systematic-review · PMID 37429996 +1 more outcome →
GlycineResearch score 58/100 · Moderate	1 systematic review/meta-analysis — 3 studies	5/6 outcomes showed benefit Sleep in healthy adults (small studies, high risk of bias)Reported a benefit — measurement not reportedbenefit2024 study ↗ Exact figures No figures reported · Follow-up: Not reported · Sample (as reported): Not reported · Recorded unit: Not reported · The effect of glycine administration on the characteristics of physiological systems in human adults: A systematic review · Systematic Review · systematic-review · PMID 37851316 Sleep-related outcomes in oral glycine trialsReported a benefit — measurement not reportedbenefit2026 study ↗ Exact figures No figures reported · Follow-up: Not reported · Sample (as reported): Not reported · Recorded unit: Not reported · Glycine Bioavailability and Sleep-Related Outcomes Following Oral Glycine and Collagen Supplementation-A Scoping Review · Journal Article · other · PMID 42687500 Daytime fatigue after partial sleep restrictionReported a benefit — measurement not reportedbenefit2012 study ↗ Exact figures No figures reported · Follow-up: Not reported · Sample (as reported): Not reported · Recorded unit: Not reported · The effects of glycine on subjective daytime performance in partially sleep-restricted healthy volunteers · Journal Article · other · PMID 22529837 Daytime sleepiness after partial sleep restrictionUnclear result — measurement not reportedunclear2012 study ↗ Exact figures No figures reported · Follow-up: Not reported · Sample (as reported): Not reported · Recorded unit: Not reported · The effects of glycine on subjective daytime performance in partially sleep-restricted healthy volunteers · Journal Article · other · PMID 22529837 +2 more outcomes →

Important: This page reflects observational, aggregate-only community reporting and independent published research. It is not medical advice, and it does not claim any compound treats, cures, or is effective for any condition. Always consult a qualified healthcare professional before starting, stopping, or changing any supplement or treatment.

No community reports published yet.

We publish sleep issues results only once at least 10 people report on the same compound, so no individual report is ever shown.

Glycine
Research saysResearch score 58/100 · Moderate3 of 3 studies reported at least one benefit
People reportNot published yet — needs 10 or more reports
Melatonin
Research saysResearch score 58/100 · Moderate2 of 2 studies reported at least one benefit
People reportNot published yet — needs 10 or more reports

Used something for sleep issues? Share how it went — only ever published in a group of 10 or more.

Add your outcome

Peer-reviewed research.

Every study behind the numbers above is linked next to its result.

57 more papers, not summarised above

Strongest evidence first.

01The effects of oral cannabidiol supplementation on blood pressure in adults: a systematic review of randomised controlled trialsRoberts A, et al. · Journal of cannabis research · 2026

Systematic Review · matched via Sleep · PubMed record (CORPUS-A)

PMID 42321899 ↗02Dysregulation of melatonin rhythm in Parkinson's and Huntington's disease: a systematic review and meta-analysisSuram RP, et al. · Frontiers in aging neuroscience · 2025

Systematic Review · matched via Sleep · PubMed record (CORPUS-A)

PMID 41143249 ↗03Effects of Dietary Supplementation in Patients with Restless Legs Syndrome: A Systematic ReviewGonzález-Parejo P, et al. · Nutrients · 2024

Systematic Review · matched via Sleep · open-access full text · PubMed record (CORPUS-A)

PMID 39064758 ↗04Sleep disturbances and female infertility: a systematic reviewLi J, et al. · BMC women's health · 2024

Systematic Review · matched via Sleep · PubMed record (CORPUS-A)

PMID 39707272 ↗05The Role of Magnesium in Sleep Health: a Systematic Review of Available LiteratureArab A, et al. · Biological trace element research · 2023

Systematic Review · matched via Sleep · PubMed record (CORPUS-A)

PMID 35184264 ↗06Blue-light filtering spectacle lenses for visual performance, sleep, and macular health in adultsSingh S, et al. · The Cochrane database of systematic reviews · 2023

Systematic Review · matched via Sleep · PubMed record (CORPUS-A)

PMID 37593770 ↗07A Systematic Review of the Efficacy and Safety of Over-the-Counter Medications Used in Older People for the Treatment of Primary insomniaAlmond SM, et al. · The Senior care pharmacist · 2021

Systematic Review · matched via Sleep · PubMed record (CORPUS-A)

PMID 33509331 ↗08Effects of exogenous melatonin on sleep quality and menopausal symptoms in menopausal women: a systematic review and meta-analysis of randomized controlled trialsYi M, et al. · Menopause (New York, N.Y.) · 2021

Meta-Analysis · matched via Sleep · PubMed record (CORPUS-A)

PMID 33784263 ↗09Oral magnesium supplementation for insomnia in older adults: a Systematic Review & Meta-AnalysisMah J, et al. · BMC complementary medicine and therapies · 2021

Meta-Analysis · matched via Sleep · PubMed record (CORPUS-A)

PMID 33865376 ↗10Approved cannabinoids for medical purposes - Comparative systematic review and meta-analysis for sleep and appetiteSpanagel R, et al. · Neuropharmacology · 2021

Meta-Analysis · matched via Sleep · PubMed record (CORPUS-A)

PMID 34181977 ↗11Therapeutic role of melatonin in migraine prophylaxis: A systematic reviewLong R, et al. · Medicine · 2019

Systematic Review · matched via Sleep · PubMed record (CORPUS-A)

PMID 30653130 ↗12Natural Products from Single Plants as Sleep Aids: A Systematic ReviewKim J, et al. · Journal of medicinal food · 2018

Systematic Review · matched via Sleep · PubMed record (CORPUS-A)

PMID 29356580 ↗13Cannabis withdrawal and sleep: A systematic review of human studiesGates P, et al. · Substance abuse · 2016

Systematic Review · matched via Sleep · PubMed record (CORPUS-A)

PMID 25893849 ↗14Non-pharmacological interventions for sleep promotion in the intensive care unitHu RF, et al. · The Cochrane database of systematic reviews · 2015

Meta-Analysis · matched via Sleep · PubMed record (CORPUS-A)

PMID 26439374 ↗15The effects of cannabinoid administration on sleep: a systematic review of human studiesGates PJ, et al. · Sleep medicine reviews · 2014

Systematic Review · matched via Sleep · PubMed record (CORPUS-A)

PMID 24726015 ↗16A systematic review of valerian as a sleep aid: safe but not effectiveTaibi DM, et al. · Sleep medicine reviews · 2007

Systematic Review · matched via Sleep · PubMed record (CORPUS-A)

PMID 17517355 ↗17A Randomized Controlled Trial of the Safety and Efficacy of Dronabinol for Agitation in Alzheimer's DiseaseRosenberg PB, et al. · The American journal of geriatric psychiatry : official journal of the American Association for Geriatric Psychiatry · 2026

Randomized Controlled Trial · matched via Sleep · PubMed record (CORPUS-A)

PMID 41350162 ↗18Cannabinol for Acute Treatment of Insomnia Disorder in a Randomized Placebo-Controlled Crossover TrialLavender IG, et al. · Journal of sleep research · 2026

Randomized Controlled Trial · matched via Sleep · PubMed record (CORPUS-A)

PMID 41698831 ↗19Effects of magnesium and potassium supplementation on insomnia and sleep hormones in patients with diabetes mellitusKhalid S, et al. · Frontiers in endocrinology · 2024

Randomized Controlled Trial · matched via Sleep · PubMed record (CORPUS-A)

PMID 39534260 ↗2012-week melatonin intake attenuates cardiac autonomic dysfunction and oxidative stress in multiple sclerosis patients: a randomized controlled trialJallouli S, et al. · Metabolic brain disease · 2024

Randomized Controlled Trial · matched via Sleep · PubMed record (CORPUS-A)

PMID 39630381 ↗21Alleviation of Pain, PAIN Interference, and Oxidative Stress by a Novel Combination of Hemp Oil, Calamari Oil, and Broccoli: A Randomized, Double-Blind, Placebo-Controlled TrialCarlisle C, et al. · Nutrients · 2023

Randomized Controlled Trial · matched via Sleep · PubMed record (CORPUS-A)

PMID 37375558 ↗22Correlates of treatment engagement and client outcomes: results of a randomised controlled trial of nabiximols for the treatment of cannabis use disorderMills L, et al. · Substance abuse treatment, prevention, and policy · 2022

Randomized Controlled Trial · matched via Sleep · PubMed record (CORPUS-A)

PMID 36209081 ↗23Effect of short-term magnesium supplementation on anxiety, depression and sleep quality in patients after open-heart surgerySaba S, et al. · Magnesium research · 2022

Controlled Clinical Trial · matched via Sleep · PubMed record (CORPUS-A)

PMID 36354243 ↗24Sleep, Growth, and Puberty After 2 Years of Prolonged-Release Melatonin in Children With Autism Spectrum DisorderMalow BA, et al. · Journal of the American Academy of Child and Adolescent Psychiatry · 2021

Randomized Controlled Trial · matched via Sleep · PubMed record (CORPUS-A)

PMID 31982581 ↗25Resetting the late timing of 'night owls' has a positive impact on mental health and performanceFacer-Childs ER, et al. · Sleep medicine · 2019

Randomized Controlled Trial · matched via Sleep · PubMed record (CORPUS-A)

PMID 31202686 ↗26Magnesium supplementation improves indicators of low magnesium status and inflammatory stress in adults older than 51 years with poor quality sleepNielsen FH, et al. · Magnesium research · 2010

Randomized Controlled Trial · matched via Sleep · PubMed record (CORPUS-A)

PMID 21199787 ↗27A feasibility study of valerian extract for sleep disturbance in person with arthritisTaibi DM, et al. · Biological research for nursing · 2009

Randomized Controlled Trial · matched via Sleep · PubMed record (CORPUS-A)

PMID 19114414 ↗28Dietary Protocols to Promote and Improve Restful Sleep: A Narrative ReviewConti F · Nutrition reviews · 2026