Medical Disclaimer: Jet lag is a temporary circadian misalignment. Melatonin is a supplement, not a drug. Consult a healthcare provider before using if pregnant, nursing, on anticoagulants, immunosuppressants, or have autoimmune conditions.
Key Takeaways
- Direction matters: Eastward travel (phase advance) is harder than westward (phase delay). Body naturally delays ~1h/day; advances only ~30–60 min/day.
- Light is the primary zeitgeber. Bright light at target “morning” + darkness at target “night” = fastest adaptation.
- Melatonin 0.5mg at target bedtime accelerates phase shift (advance for east, delay for west). Low dose = physiologic; high dose = grogginess.
- Pre-adaptation works: Shift schedule 1h/day × days before travel = arrival pre-adapted.
- No magic pill. Caffeine, hydration, meal timing support — but light + melatonin + schedule = core protocol.
The Physiology: Why Jet Lag Happens
- Circadian period (tau) = 24.2h average. Body naturally drifts later (delay) without light cues.
- Phase Response Curve (PRC): Light before core body temp minimum (CBTmin) = phase delay. Light after CBTmin = phase advance.
- CBTmin ≈ 2h before habitual wake time. For 7 AM waker: CBTmin ~5 AM.
- Melatonin PRC opposite: Melatonin before CBTmin = phase advance. Melatonin after CBTmin = phase delay.
Protocol by Direction
Eastward Travel (Phase Advance) — Harder
Example: NYC → London (5h advance). Body needs to shift earlier.
| Timing | Action | Rationale |
|---|---|---|
| Pre-travel (3–5 days) | Wake 1h earlier daily; bright light 10k lux × 30 min at new wake; melatonin 0.5mg at new bedtime | Pre-adaptation; each day shifts ~30–60 min |
| Flight day | Set watch to destination time immediately | Psychological anchoring |
| During flight | Sleep only if matches destination night; eye mask, earplugs, compression socks | Align sleep pressure with destination |
| Arrival morning | Bright light 10k lux × 30–60 min ASAP; caffeine 100–200mg | Phase advance signal; alertness |
| Arrival afternoon | Avoid bright light (sunglasses if outside); no nap >20 min | Prevent phase delay; maintain advance clock-wake pressure |
| Arrival bedtime | Melatonin 0.5mg 30 min pre-target bedtime; cool, dark, quiet | Phase advance reinforcement |
| Days 1–3 | Repeat: morning light 10k lux × 30 min; melatonin 0.5mg at bedtime; no naps | Consolidate advance; ~1h/day shift |
Westward Travel (Phase Delay) — Easier
Example: London → NYC (5h delay). Body naturally delays.
| Timing | Action | Rationale |
|---|---|---|
| Pre-travel (2–3 days) | Wake 30 min later daily; evening bright light 2,500 lux × 30 min; melatonin 0.5mg at current bedtime (optional) | Gentle pre-adaptation; body delays easily |
| Flight day | Set watch to destination; stay awake during destination day | Align with new schedule |
| During flight | Stay awake during destination day; sleep only if destination night | Build sleep pressure for new night |
| Arrival evening | Bright light 2,500–10,000 lux × 30 min (if before CBTmin); caffeine if needed | Phase delay signal; extend wakefulness |
| Arrival bedtime | Melatonin 0.5mg 30 min pre-bed (optional); cool, dark | Phase delay reinforcement |
| Days 1–3 | Evening light 2,500 lux × 30 min; melatonin 0.5mg at bedtime; morning darkness | Consolidate delay; ~1–1.5h/day shift |
Pre-Adaptation: The Pro Strategy
- Calculate shift needed: Destination time − Origin time = hours to shift.
- Days available: Days before travel.
- Daily shift target: East = 30–60 min/day advance. West = 60–90 min/day delay.
- Start: (Hours to shift) ÷ (Daily shift) = Days needed. Start that many days before.
- Example: NYC→Tokyo (13h advance). 13h ÷ 45 min/day = 17 days. Start 2.5 weeks before.
If insufficient time: Prioritize first 3 days post-arrival protocol. Accept partial adaptation.
Melatonin Protocol Details
| Parameter | Recommendation |
|---|---|
| Dose | 0.5mg (physiologic) — NOT 3–5mg |
| Form | Immediate-release (not extended-release) |
| Timing (East) | Target bedtime − 30 min |
| Timing (West) | Target bedtime − 30 min (optional; less critical) |
| Duration | 3–5 days post-arrival |
| Quality | USP/NSF verified; 0.5mg tablet or liquid |
| Contraindications | Pregnancy, autoimmune, anticoagulants, immunosuppressants, seizure disorder |
Supporting Strategies (Evidence-Graded)
| Strategy | Grade | Protocol |
|---|---|---|
| Caffeine (strategic) | B | 100–200mg at target morning; avoid after target noon |
| Hydration | C | 250ml/h flight; avoid alcohol (↑ fragmentation, dehydration) |
| Meal Timing | C | Eat at destination meal times immediately; protein at “breakfast,” lighter at “dinner” |
| Exercise | C | Light activity at target morning; avoid intense <3h pre-bed |
| Pycnogenol / Pine Bark | D | Small RCT: 150mg/day → ↓ jet lag score; mechanism unclear |
| Viagra (sildenafil) | D | 1 RCT (hamsters): accelerated re-entrainment; NOT for humans |
Quick Reference Cards
NYC → London (5h East)
- Pre: 5 days × 1h advance (wake 6→1 AM, light 5 AM, melatonin 9 PM)
- Flight: Sleep first half (matches London night)
- Arrival: Light 7 AM, melatonin 10 PM, no naps
- Days 1–3: Light 7 AM, melatonin 10 PM
LA → Tokyo (16h East = 8h West)
- Shorter shift: 8h delay (westward) easier than 16h advance
- Pre: 3 days × 2.5h delay (wake later, evening light)
- Flight: Stay awake Tokyo day, sleep Tokyo night
- Arrival: Evening light, melatonin bedtime
Sydney → LA (17h West = 7h East)
- Shorter shift: 7h advance (eastward) harder
- Pre: 10 days × 45 min advance (or accept partial)
- Flight: Sleep LA night (matches Sydney day — hard)
- Arrival: Morning light critical, melatonin 10 PM
Frequently Asked Questions
Can I use sleeping pills (zolpidem) for jet lag?
Short-acting hypnotics (zolpidem 5–10mg) can help sleep initiation first 1–2 nights but don’t shift circadian rhythm. Risk: dependence, next-day impairment, complex sleep behaviors. Use only if insomnia severe; max 2–3 nights.
Does flying business/first class reduce jet lag?
Better sleep opportunity (lie-flat) → less sleep debt on arrival. But circadian shift still required. Net: slightly easier adaptation, not prevention.
What about children / infants?
No melatonin for children without pediatrician. Strategy: immediate destination schedule, light exposure, patience. Kids adapt faster (~1–2 days per hour). Prioritize sleep pressure (activity, no naps off-schedule).
References
- Waterhouse J, et al. “Jet Lag: Trends and Coping Strategies.” Lancet. 2007;369(9567):1117-1129.
- Herxheimer A, Petrie KJ. “Melatonin for the Prevention and Treatment of Jet Lag.” Cochrane Database. 2002;(2):CD001520.
- Burgess HJ, et al. “Bright Light and Melatonin for Phase Advancing.” J Biol Rhythms. 2010;25(5):372-380.
- Paul MA, et al. “Impact of Caffeine on Jet Lag Recovery.” Aviat Space Environ Med. 2006;77(4):408-413.
- Sack RL, et al. “Circadian Rhythm Sleep Disorders.” Sleep. 2007;30(11):1460-1483.