JET LAG
UW MEDICINE
| UW NEIGHBORHOOD CLINICS
Jet lag symptoms are common for international travel. It relates to the body's normal day/night
rhythm getting out of sync. The body normally has a cycle in which melatonin (a natural
hormone
that aligns sleep cycles and other physiological functions) reaches peak blood levels at around 2 a.m.
When crossing time zones, this peak needs to be adjusted (shifted) so that it always peaks at this
time of the night. Because of the changed time zones, misalignment of the cycle occurs, giving many
but not all travelers symptoms of jet lag. The range of symptoms includes sleep disturbances,
daytime fatigue, weakness, headache, sleepiness, and irritability. Most symptoms disappear by the
fifth day after traveling across a 6-hour time zone. It is difficult to compensate for jet lag for trips
shorter than 3 days and some would advise against attempting to do so.
One way of shifting the melatonin peak to its physiological position is to take melatonin tablets and
push or pull the peak blood levels by timing the tablets appropriately. To use melatonin, please
follow the schedule below. Your provider may prescribe something similar aside from melatonin.
Eastward Travel
•
Away for 4 or more days: When traveling eastward, take a 5mg melatonin tablet at 1800
to1900 hours local time (6 p.m. to 7 p.m.) on the day of departure (if necessary, take while
on the flight). On arrival, take a tablet at local bed time, 2200 to 2300 hours (10 p.m. to 11
p.m.), for the next 4 days.
•
Away for less than 4 days: The evening preceding departure, take a dose of melatonin at
1800 to 1900 hours (6 p.m.-7 p.m.) local time. On arrival, take a daily dose at local bedtime,
2200 to 2300 hours (10 p.m. to 11 p.m.), until departure.
Westward Travel
•
Away for 4 or more days: When traveling westward, take 1 tablet daily at local bedtime,
2300 hours (11pm) or later, for 4 days at the destination (or at each stop-over). If the
traveler awakes in the very early hours of the morning (before 4am), he/she can take
another capsule. Do not take melatonin pre-flight when flying west.
•
Away for less than four days: Take melatonin at bedtime the night before departure.
Cautions
Melatonin can produce sleepiness and reduced alertness. Persons taking melatonin should not
drive, operate heavy machinery, or perform tasks requiring alertness for 4 to 5 hours after
taking melatonin. The timing of the dose of melatonin needs to be precise, since mistiming the
dose can worsen rather than improve the jet lag symptoms. Persons who suffer from psychiatric
problems or migraine headaches or who may be or intend to become pregnant should use
melatonin with caution, if at all.
Zolpidem (Ambien) and Other Hypnotics
Zolpidem (10mg) has been shown as effective as melatonin alone or as melatonin/zolpidem in
combination. Zolpidem should be used to induce sleep after arrival at the appropriate
destination time-zone sleeping time, when the body is jet-lagged and cannot fall asleep. It can be
used for up to 2 or 3 nights at each end of the trip. Zolpidem has a short half-life with no
residual effect in the morning. Travelers should resist the temptation to sleep during the day
the first few days at destination, since this will decrease the ability to sleep at night and prolong
the adjustment cycle. Other short-active hypnotics have been recommended (zaleplon,
temazepam, and triazolam) but have not been studied formally in the way that zolpidem has.
Sedatives are no longer recommended on airline flights due to the risk of blood clots in the legs
during prolonged immobility.
Other Ways to Reduce Jet Lag
Some ways of trying to reduce jet lag include the following:
•
When possible, choose daytime flights to minimize loss of sleep and fatigue.
•
Avoid large fatty meals, caffeine, and alcohol during the flight.
•
Drink lots of water.
•
Regular timed exposure to daytime outdoor light or high intensity artificial light
(>10,000 LUX) can be useful in improving jet lag.
•
There is no current evidence to the usefulness of homeopathic remedies or diet in the
treatment or prevention of jet lag.
Adapted from Travax’s Medical Library
Pamela Yung, M.D., is a board-certified family medicine physician at the UW Neighborhood Factoria Clinic.
For more information, call 877.520.5000 or visit
www.uwmedicine.org/uwnc.