Sleep Aid for Travel Across Time Zones
For healthy adults traveling across 5 or more time zones, melatonin 5 mg fast-release formulation taken at the target bedtime (10 PM to midnight) at the destination is the recommended sleep aid, as it is remarkably effective in preventing or reducing jet lag with a number needed to treat of 2. 1, 2
Primary Recommendation: Melatonin
Dosing and Formulation
- Use 5 mg fast-release melatonin rather than slow-release formulations, as the short-lived higher peak concentration works better for jet lag 1, 3
- Doses between 0.5 mg and 5 mg are similarly effective for reducing jet lag symptoms, but 5 mg produces faster sleep onset and better sleep quality 1, 3
- Doses above 5 mg provide no additional benefit 1, 2
Timing is Critical
- Take melatonin close to target bedtime at the destination (10 PM to midnight) to align circadian rhythms with local time 1, 2
- Do not take melatonin early in the day, as this causes sleepiness and delays adaptation to local time 1, 2
- Continue for several days after arrival as needed 3
Expected Benefits
- Melatonin significantly improves self-rated sleep quality, shortens sleep latency, and reduces fatigue and daytime sleepiness after intercontinental flights 3
- The benefit is greater when crossing more time zones and is particularly effective for eastward travel 1, 2
- For travel across 2-4 time zones, melatonin can still be used if needed, though the benefit may be less pronounced 1, 2
Safety Considerations
Medical Oversight Required
- All pharmacological sleep interventions, including melatonin, should be overseen by a medical doctor 4
- People with epilepsy should avoid melatonin due to case reports of adverse effects 4, 1, 2
- Potential interaction with warfarin has been reported and requires investigation 4, 1, 2
Side Effect Profile
- The incidence of side effects with melatonin is low, and occasional short-term use appears safe 1, 2
- Side effects from the preflight adjustment protocols are minimal 5
Complementary Strategies
Light Exposure Management
- Light is the most powerful external regulator of circadian rhythms and should be combined with melatonin for optimal results 6, 4
- Strategic light exposure after arrival helps facilitate circadian rhythm adjustment 6
Additional Options
- Slow-release caffeine or a combination of caffeine and melatonin may help reduce jet lag symptoms 6, 4
- Sleep hygiene practices should always be considered first before pharmacological interventions 6, 4
- Avoid alcohol during flights as it alters cognitive function, triggers anxiety, and disrupts sleep 4
- Maintain appropriate hydration while avoiding excessive caffeine or tea during flights 4
What NOT to Use
Antihistamines Are Not Recommended
- Over-the-counter antihistamines (diphenhydramine, hydroxyzine) are not recommended for sleep aid during travel due to lack of efficacy data and safety concerns 7
- These agents cause significant daytime sedation, anticholinergic effects, and psychomotor impairment 7
Melatonin for Chronic Insomnia vs. Jet Lag
- While the American Academy of Sleep Medicine suggests against using 2 mg melatonin for chronic insomnia treatment due to lack of efficacy 6, this does not apply to jet lag management, where melatonin has strong evidence of effectiveness 1, 2
- The context differs: jet lag involves acute circadian misalignment, not chronic insomnia 1, 2
Important Caveats
Performance Decrements
- Speed and power may be reduced for up to 72 hours following travel across multiple time zones (>4-5 zones) and long-haul flights (>15 hours) 6, 4
- The severity of jet lag is proportional to the number of time zones crossed and cumulative sleep loss 6, 4