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Medical Author:

John P. Cunha, DO, FACOEP

John P. Cunha, DO, FACOEP

John P. Cunha, DO, is a U.S. board-certified Emergency Medicine Physician. Dr. Cunha's educational background includes a BS in Biology from Rutgers, the State University of New Jersey, and a DO from the Kansas City University of Medicine and Biosciences in Kansas City, MO. He completed residency training in Emergency Medicine at Newark Beth Israel Medical Center in Newark, New Jersey.

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Medical Editor:

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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In this Article

• What is jet lag?
• What are other symptoms and signs of jet lag?
• What is a time zone?
• Why does jet lag occur?
• How does the body keep time?
• What is the role of melatonin in jet lag?
• Does the direction of travel matter?
• Do the symptoms of jet lag vary in intensity?
• How long does jet lag last?
• What are the best ways to cope with jet lag?
• Should I take melatonin?
• Patient Comments: Jet Lag - Remedies
• Patient Comments: Jet Lag - Symptoms
• Jet Lag Index

Another option is synthetic melatonin, which is classified in the U.S. as a dietary supplement. A study in the British Medical Journal in 1989 reported that taking synthetic melatonin tablets can help travelers restore normal sleeping patterns. In that study, 20 volunteers traveling back and forth between New Zealand and England took daily doses of either 5 mg of melatonin or a placebo (a blank, or sugar pill) before, during, and after their flights. Those taking melatonin returned to their normal sleep patterns in 2.85 days on average compared with 4.15 days for those taking a placebo.

However, scientists in the U.S. and many other countries are not yet convinced that enough evidence exists to prove the efficacy of over-the-counter (OTC) melatonin tablets. These scientists also point out the following:

1. No information has been compiled on the long-term effects of taking melatonin.

2. No watchdog measures are in place to assure that all OTC melatonin products meet minimum standards.

In 2005, MIT released the results of a meta-analysis of 17 peer-reviewed studies using melatonin. It showed that melatonin was effective in helping people fall asleep at doses of 0.3 mg. Larger doses of melatonin seem to be less effective after only a few days' use.

For the purpose of treating jet lag, it is suggested that a dose between 0.3 mg and 5 mg of melatonin be taken on the first day you travel at the time you will want to go to sleep at your destination. This may be continued at bedtime for a few days once you are at your destination. Melatonin seems to be most effective when crossing five or more time zones, or traveling east.

Be aware that higher doses of melatonin can cause sleepiness, lethargy, confusion, and decreased mental sharpness. Operating motor vehicles or heavy machinery should be avoided after taking your daily dose of melatonin. Consult your health-care provider if you plan on taking melatonin.

REFERENCES:

Breus, Michael J. "How Long Does Jet Lag Last?" WebMD.com. Dec. 14, 2010. <http://answers.webmd.com/answers/1195390/How-long-does-jet-lag-last>.

Herxheimer, A., and K.J. Petrie. "Melatonin for the Prevention and Treatment of Jet Lag." Cochrane Database Syst. Rev. 2 (2002). <http://www.ncbi.nlm.nih.gov/pubmed/12076414>.

"Melatonin and Sleep." National Sleep Foundation. <http://www.sleepfoundation.org/article/sleep-topics/melatonin-and-sleep>.

"Sleep and Circadian Rhythm Disorders." WebMD.com. Mar. 3, 2010. <http://www.webmd.com/sleep-disorders/guide/circadian-rhythm-disorders-cause>.

United States. National Institute of General Medical Sciences. "Circadian Rhythms Fact Sheet." July 2008. <http://www.nigms.nih.gov/Education/Factsheet_CircadianRhythms.htm>.