Travel Health Evidence

Evidence map

Jet lag: what the evidence base looks like

20 publications, 9 of them trials and 7 syntheses. This page describes the shape of that literature rather than summarising its conclusions.

Updated 4 min read 20 citations

Empty single-aisle airliner cabin looking down rows of seats towards the rear
Long periods seated with the knees bent are the main reason immobility is linked with travel-related clots. Kevin Dooley · CC BY 2.0 · Wikimedia Commons
What the evidence on jet lag is made of Of 20 publications on this topic, the breakdown by study type: 7 meta-analysis, 9 randomised trial, 4 review. 794meta-analysis (7)randomised trial (9)review (4)
20 publications, by study type. Volume is not strength — the same count can be a settled question or a pile of commentary, and which one it is depends almost entirely on this breakdown. Harvested from PubMed and Crossref; publication type as recorded by the source.

What this literature is made of

This is a well-developed evidence base: multiple syntheses sitting on a substantial body of trials. Questions here are usually about applicability rather than about whether an effect exists.

The distinction that matters most is between synthesis and primary research. A meta-analysis pools trials and is the closest thing to a settled answer a field produces. A narrative review is one group's reading of the same material and can be selective without being dishonest. Counting them together, which most citation counts do, obscures exactly the thing you want to know.

When the jet lag literature was published Publication years for the 20 papers on this topic, grouped into bands from before 2015 through to 2023 onwards. Before 20159 papers2015-20196 papers2020-20223 papers2023 onwards2 papers
Still active. The most recent paper here is from 2025, so this is a field where an answer written today may not hold for long. Publication years as recorded by PubMed and Crossref.

How this page is built

Everything above is computed from the citations this site harvested from PubMed and Crossref, not written by hand. When the weekly harvest finds a new paper on this topic, these counts change and the characterisation changes with them. That is the point: a hand-written claim about how strong an evidence base is starts decaying the day it is written.

Publication type is taken as the source records it. That is imperfect — journals label inconsistently, and a paper indexed as a "review" may be a systematic one — so treat the bands as approximate. They are accurate enough to distinguish a trial literature from a commentary literature, which is the distinction that matters.

Interior of an old British railway carriage with facing upholstered seats and a window
Gemma Evans stayandroam · CC0 · Wikimedia Commons

The strongest work on this topic

Ordered by study design first, then recency. The full set is listed in the references below.

  1. Social jet lag and mental health outcomes: A systematic review and meta-analysis — Gao L, Gao J, Zeng Z, 2025, meta-analysis
  2. Evening wear of blue-blocking glasses for sleep and mood disorders: a systematic review — Hester L, Dang D, Barker CJ et al., 2021, systematic review
  3. How to manage travel fatigue and jet lag in athletes? A systematic review of interventions — Janse van Rensburg DCC, Jansen van Rensburg A, Fowler P et al., 2020, systematic review
  4. Workplace lighting for improving alertness and mood in daytime workers — Pachito DV, Eckeli AL, Desouky AS et al., 2018, meta-analysis
  5. Is melatonin useful for jet lag? — Tortorolo F, Farren F, Rada G, 2015, meta-analysis
  6. The effectiveness of melatonin for promoting healthy sleep: a rapid evidence assessment of the literature — Costello RB, Lentino CV, Boyd CC et al., 2014, systematic review
  7. Melatonin for preventing and treating jet lag — Herxheimer A, Petrie KJ, 2001, systematic review
  8. Daytime eating during simulated night work mitigates changes in cardiovascular risk factors: secondary analyses of a randomized controlled trial — Chellappa SL, Gao L, Qian J et al., 2025, randomised controlled trial
  9. Sleep Hygiene and Light Exposure Can Improve Performance Following Long-Haul Air Travel — Fowler PM, Knez W, Thornton HR et al., 2021, randomised controlled trial
  10. Resetting the late timing of 'night owls' has a positive impact on mental health and performance — Facer-Childs ER, Middleton B, Skene DJ et al., 2019, randomised controlled trial
How much research is there on jet lag?
20 publications are indexed here, of which 9 are trials and 7 are syntheses.
Does more research mean a stronger conclusion?
No. Composition matters more than volume — five randomised trials support a claim far better than fifty commentaries, and citation counts do not distinguish between them.
How current is this?
The most recent paper indexed here is from 2025. The set is refreshed weekly from PubMed and Crossref.
Why does this page not tell me the answer?
Because summarising a literature into a conclusion requires reading it, and doing that automatically is how confident nonsense gets published. This page tells you how much weight a conclusion could bear; the articles on this site do the interpreting.

References

Every citation below links to the original peer-reviewed record on PubMed or via DOI. Nothing here is a substitute for medical advice.

  1. Social jet lag and mental health outcomes: A systematic review and meta-analysis Gao L, Gao J, Zeng Z · Acta psychologica · 2025 · Meta-analysis DOIPubMed 40818420
  2. Evening wear of blue-blocking glasses for sleep and mood disorders: a systematic review Hester L, Dang D, Barker CJ, et al. · Chronobiology international · 2021 · Systematic review DOIPubMed 34030534
  3. How to manage travel fatigue and jet lag in athletes? A systematic review of interventions Janse van Rensburg DCC, Jansen van Rensburg A, Fowler P, et al. · British journal of sports medicine · 2020 · Systematic review DOIPubMed 32303523
  4. Workplace lighting for improving alertness and mood in daytime workers Pachito DV, Eckeli AL, Desouky AS, et al. · The Cochrane database of systematic reviews · 2018 · Meta-analysis DOIPubMed 29498416Full text
  5. Is melatonin useful for jet lag? Tortorolo F, Farren F, Rada G · Medwave · 2015 · Meta-analysis DOIPubMed 26731279
  6. The effectiveness of melatonin for promoting healthy sleep: a rapid evidence assessment of the literature Costello RB, Lentino CV, Boyd CC, et al. · Nutrition journal · 2014 · Systematic review DOIPubMed 25380732Full text
  7. Melatonin for preventing and treating jet lag Herxheimer A, Petrie KJ · The Cochrane database of systematic reviews · 2001 · Systematic review DOIPubMed 11279722Full text
  8. Daytime eating during simulated night work mitigates changes in cardiovascular risk factors: secondary analyses of a randomized controlled trial Chellappa SL, Gao L, Qian J, et al. · Nature communications · 2025 · Randomised controlled trial DOIPubMed 40199860Full text
  9. Sleep Hygiene and Light Exposure Can Improve Performance Following Long-Haul Air Travel Fowler PM, Knez W, Thornton HR, et al. · International journal of sports physiology and performance · 2021 · Randomised controlled trial DOIPubMed 33152686
  10. Resetting the late timing of 'night owls' has a positive impact on mental health and performance Facer-Childs ER, Middleton B, Skene DJ, et al. · Sleep medicine · 2019 · Randomised controlled trial DOIPubMed 31202686
  11. A 30-Minute, but Not a 10-Minute Nighttime Nap is Associated with Sleep Inertia Hilditch CJ, Centofanti SA, Dorrian J, et al. · Sleep · 2016 · Randomised controlled trial DOIPubMed 26715234Full text
  12. Glucocorticoids entrain molecular clock components in human peripheral cells Cuesta M, Cermakian N, Boivin DB · FASEB journal : official publication of the Federation of American Societies for Experimental Biology · 2015 · Randomised controlled trial DOIPubMed 25500935
  13. Transcranial bright light and symptoms of jet lag: a randomized, placebo-controlled trial Jurvelin H, Jokelainen J, Takala T · Aerospace medicine and human performance · 2015 · Randomised controlled trial DOIPubMed 25945550
  14. Effectiveness and tolerability of melatonin and zolpidem for the alleviation of jet lag Suhner A, Schlagenhauf P, Höfer I, et al. · Aviation, space, and environmental medicine · 2001 · Randomised controlled trial PubMed 11471907
  15. A double-blind trial of melatonin as a treatment for jet lag in international cabin crew Petrie K, Dawson AG, Thompson L, et al. · Biological psychiatry · 1993 · Randomised controlled trial DOIPubMed 8513037
  16. Effect of melatonin on jet lag after long haul flights Petrie K, Conaglen JV, Thompson L, et al. · BMJ (Clinical research ed.) · 1989 · Randomised controlled trial DOIPubMed 2496815Full text
  17. Melatonin agonists and insomnia Ferguson SA, Rajaratnam SM, Dawson D · Expert review of neurotherapeutics · 2010 · Review DOIPubMed 20136385
  18. Circadian rhythm disorders Reid KJ, Zee PC · Seminars in neurology · 2009 · Review DOIPubMed 19742414
  19. Melatonin for primary insomnia? Drug and therapeutics bulletin · 2009 · Review DOIPubMed 19567841
  20. Melatonin and clinical application Wetterberg L · Reproduction, nutrition, development · 1999 · Review DOIPubMed 10420439