Melatonin for Shift Work Adaptation
Melatonin taken before daytime sleep is the best-evidenced supplement for shift workers.
Overview
Verdict
Cochrane evidence across 718 participants shows melatonin extends post-shift daytime sleep by about 24 minutes, with no improvement in sleep onset latency or on-shift alertness.
How It Works
Downstream effects
Dosing & Protocol
Doses used in human trials
| Population | Dose | Timing | Notes |
|---|---|---|---|
| Night shift workers | 1-3 mg immediate release | Immediately before daytime sleep | The dose range across most shift-work trials |
| Lower physiological dose | 0.5 mg | Before daytime sleep | Often as effective as higher doses with less grogginess |
| Higher trial arms | 5-10 mg | Before daytime sleep | No consistent added benefit; more next-sleep hangover |
| Prolonged release | 2 mg | Before daytime sleep | Designed for sleep maintenance; licensed for older adults in some countries |
Timing matters more than dose. Melatonin taken at the wrong clock time can shift the body clock in the unwanted direction.
Simple protocol
- 1
Set expectations to match the evidence
Expect roughly half an hour more daytime sleep, not faster sleep onset and not sharper nights.
- 2
Take 0.5-3 mg right before daytime sleep· Across the run of night shifts
Consistency of timing matters more than the size of the dose.
- 3
Wear dark glasses on the commute home
Morning light is the strongest signal telling your clock to stay on a day schedule.
- 4
Make the bedroom genuinely dark and quiet
Blackout blinds and earplugs do more for daytime sleep than any supplement.
- 5
Use bright light during the shift
This is the intervention that addresses on-shift alertness, which melatonin does not.
- 6
Do not drive within five hours of a dose
Drowsiness is the main practical risk.
Evidence
Studies linked to this pairing.
Melatonin for shift work sleep disorder and circadian adaptation: a Cochrane review
Liira J, Verbeek JH, Costa G +4 more
Melatonin increased sleep length after night shift by around 24 minutes but did not improve sleep onset latency or alertness on shift
- Sleep length after night shift
- Increased by about 24 minutes
- Sleep onset latency
- No significant improvement
- On-shift alertness
- No significant improvement
- Participants
- 718 across the Cochrane review
- Typical dose
- 0.5-3 mg before daytime sleep
- Main limitation
- Modest effect confined to sleep duration; does not address night-time alertness or long-term shift-work health risks
Safety
Sleep length, not alertness
Melatonin extends daytime sleep by roughly 24 minutes but does not make you sharper on shift. For alertness, bright light during the shift and strategic napping have better support.
Interactions & Conflicts
Interactions and cautions
| Interacts with | Severity | Mechanism | Action |
|---|---|---|---|
| Driving or safety-critical work | high | Residual drowsiness | Allow at least five hours after a dose |
| Warfarin and anticoagulants | moderate | Possible effect on clotting | Discuss with a prescriber before use |
| Fluvoxamine and other CYP1A2 inhibitors | moderate | Markedly increased melatonin levels | Reduce the dose or avoid |
| Sedatives, alcohol and benzodiazepines | moderate | Additive sedation | Avoid combining |
| Epilepsy | moderate | Mixed reports on seizure threshold | Medical advice before use |
| Pregnancy and breastfeeding | moderate | Insufficient safety data | Avoid unless advised otherwise |
References
Medical Disclaimer
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Individual results may vary. The statements on this website have not been evaluated by the Food and Drug Administration. Products and information are not intended to diagnose, treat, cure, or prevent any disease.