Melatonin for sleep: who it actually helps

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1. 1

   Meta-analysis: melatonin for the treatment of primary sleep disorders

   PLOS ONE (Ferracioli-Oda et al.)Published May 17, 2013Checked Sep 30, 2026

   “Across 19 trials with 1,683 participants, melatonin reduced time to fall asleep by about 7 minutes and increased total sleep time by about 8 minutes.”

2. 2

   Clinical practice guideline for the pharmacologic treatment of chronic insomnia in adults

   Journal of Clinical Sleep Medicine (American Academy of Sleep Medicine)Published Feb 15, 2017Checked Sep 30, 2026

   “We suggest that clinicians not use melatonin as a treatment for sleep onset or sleep maintenance insomnia (versus no treatment) in adults. (Weak recommendation.)”

3. 3

   Melatonin for the prevention and treatment of jet lag

   Cochrane Database of Systematic Reviews (Herxheimer & Petrie)Published Apr 22, 2002Checked Sep 30, 2026

   “Melatonin is remarkably effective in preventing or reducing jet lag, particularly when crossing five or more time zones and flying eastward.”

4. 4

   Melatonin natural health products and supplements: presence of serotonin and significant variability of melatonin content

   Journal of Clinical Sleep Medicine (Erland & Saxena)Published Feb 15, 2017Checked Sep 30, 2026

   “Melatonin content ranged from −83% to +478% of the labelled amount, and 26% of products contained serotonin.”

5. 5

   Quantity of melatonin and CBD in melatonin gummies sold in the US

   JAMA (Cohen et al.)Published Apr 25, 2023Checked Sep 30, 2026

   “Of 25 melatonin gummy products analysed, actual melatonin quantities ranged from 74% to 347% of the labelled amount.”

6. 6

   Do Long-Haul Travel and Jet Lag Affect Athletes' Physiological, Humoral and Performance Outcomes? A Systematic Narrative Review.

   Sports (Basel, Switzerland) (Benito et al.)Published Mar 2, 2026Checked Oct 4, 2026

   “Overall, 284 records were identified, with 89 studies included. Travel directions were equally distributed between eastward and westward journeys, crossing 1-12 time zones. Interventions to mitigate travel effects were reported in 17 studies, primarily melatonin, caffeine, and light exposure. Common physiological changes included sleep disturbances (n = 36), body temperature alterations (n = 18), blood pressure changes, hormonal shifts (n = 9), heart rate variability (n = 4), and immune alterations (n = 4). Travel effects comprised fatigue (n = 25), sleep changes (n = 21), decreased physical performance (n = 18), mood changes (n = 15), and cognitive impairments (n = 9). Physical performance outcomes included anaerobic power (n = 18), strength (n = 14), velocity (n = 12), aerobic capacity (n = 10), coordination (n = 8), and reaction time (n = 7). Long-haul travel negatively affects multiple physiological and performance domains in athletes, including sleep, hormonal balance, autonomic function, and physical performance. The magnitude of these effects seems to be influenced by travel direction, number of time zones crossed, and individual susceptibility.”

7. 7

   Pharmacological treatment of sleep disorder phenotypes in Parkinson's disease: a systematic review and meta-analysis of randomised controlled trials.

   Journal of neurology (Canever et al.)Published Sep 24, 2026Checked Oct 4, 2026

   “For overall sleep quality (k = 6), pharmacological treatment produced a statistically significant improvement in PSQI scores (MD 2.66; 95% CI 1.63 to 3.69; I2 = 71%). For insomnia symptoms (k = 3) and RBD (k = 2), pooled estimates were non-significant with high heterogeneity (I2 = 96% and 99%, respectively), precluding reliable conclusions. Given this level of heterogeneity (I2 > 90%), pooled estimates for these two domains, as well as for EDS, are presented as exploratory only and narrative synthesis is emphasised over meta-analytic pooling. No unexpected safety signals were identified, although safety reporting was heterogeneous and quantitative pooling was not performed.ConclusionsPharmacological treatment, particularly with chronobiotic agents and dopaminergic receptor agonists, may produce improvement in overall sleep quality (low-certainty evidence). Evidence for EDS, insomnia symptoms, and RBD remains insufficient for definitive recommendations, and pooled estimates in these domains should not be over-interpreted given their very high statistical heterogeneity. Phenotype-specific RCTs with harmonised outcome measures are needed.”

8. 8

   Sleep-Wake Disturbances in Pediatric Traumatic Brain Injury: A Systematic Review and Meta-Analysis of Interventions.

   Brain and behavior (Lofitou et al.)Published Sep 1, 2026Checked Oct 4, 2026

   “In contrast, melatonin did not produce statistically significant pooled effects on persistent post-concussion symptoms or cognitive outcomes, and treatment effects varied across dosage groups. Few studies examined mindfulness or educational outcomes, revealing key research gaps. Discrepancies between objective (actigraphy) and subjective (self-report) measures emphasized the need for multi-method sleep assessment.ConclusionCBT-I is the most consistently effective intervention for sleep problems following pediatric TBI. Melatonin showed mixed and nonsignificant pooled effects, indicating that its role in pediatric TBI recovery requires further investigation. Future research should focus on personalized, multidisciplinary treatment models integrating behavioral, pharmacological, and rehabilitative approaches to optimize long-term neurocognitive and educational outcomes.”

9. 9

   Safety and Efficacy of Melatonin for Sleep Disorders in Cancer: A Systematic Review and Meta-Analysis of Randomized Clinical Trials.

   Current reviews in clinical and experimental pharmacology (Abbasi et al.)Published Sep 2, 2026Checked Oct 4, 2026

   “Subgroup analysis revealed a significant decrease in the Pittsburgh Sleep Quality Index (PSQI) in US studies (SMD = -0.57, 95% CI: [-0.99, -0.14], I2 = 31.5%). Meta-analysis of the seven PSQI components showed no significant item-level improvement with melatonin treatment. Studies using non-PSQI sleep outcomes showed mixed findings, with short-term improvement in insomnia severity in one trial but modest or non-significant effects in others.DiscussionWhile the overall impact of melatonin on sleep quality was not statistically significant, subgroup analyses and qualitative evidence indicate clinically relevant benefits.ConclusionMelatonin shows promising but uncertain benefits for sleep disruptions in patients with malignancies. However, the evidence should be interpreted cautiously because of substantial clinical and statistical heterogeneity, limited sample sizes, short intervention durations, and predominantly subjective sleep measures. Larger, well-standardized randomized trials using both subjective and objective sleep assessments are needed.”