The supplement can battle jet lag for some people, but you need to know how to use it and who should not.
When you fly across the country or around the world, your internal body clock remains stuck in your departure time zone, thanks to millions of years of evolution that’s programmed it to run on a roughly 24-hour cycle. But you’ve got work to do! Or fun to have!
Melatonin supplements can serve as “a little push” to adjust the body clock amid specific short-term challenges like jet lag, said Suzanne Bertisch, MD, an assistant professor of medicine at Harvard Medical School, and director of behavioral sleep medicine at Brigham and Women’s Hospital.
Before using the supplement to change the hands of internal time, however, you’ll want to understand proper dosing and timing and potential side effects.
Does it work?
Melatonin is produced naturally in the brain’s pineal gland. It’s crucial for regulating your circadian rhythm, the body clock that tells you when to be alert and when to get sleepy. Production is stimulated by darkness and suppressed by daylight, so getting lots of natural daylight, outside and especially in early morning, is vital to setting or resetting your body clock.
The more time zones you cross, the more helpful melatonin supplements may be. There are not a lot of recent studies on it, but a 2002 review of clinical trials involving airline staff and passengers and military personnel found it can reduce or prevent jet lag, particularly when flying eastward across several time zones. A similar review in 2014 offered a more lukewarm assessment, concluding “the use of melatonin in healthy adults shows potential in preventing phase shifts due to jet lag.”
Sleep experts generally deem it potentially helpful.
When you take melatonin prior to going to bed in a new time zone, it mimics a natural melatonin spike, fooling your brain into thinking bedtime is approaching, writes Matthew Walker, PhD, a professor of neuroscience and psychology at the University of California, Berkeley and author of the book Why We Sleep.
But the effect varies by individual, and people who have no trouble falling asleep—whether jet-lagged or otherwise—should avoid it, Bertisch said.
How do I use it?
“Melatonin is not a sleeping pill. It's not a sedative,” explains Michael Grandner, PhD, a behavioral sleep medicine specialist and director of the Sleep and Health Research Program at the University of Arizona. “It mostly works by impacting your body clock to tell your body that it is night.”
Dosing and timing are key. Bertisch advises three to five milligrams, tops—which might mean splitting a typical pill in half—one hour or so before bedtime. Melatonin should not be taken after you’ve slept and woken up during the night, as that would help jumpstart a fresh cycle that could leave you drowsy the next day.
For time-zone changes, the supplement can be most effective when traveling eastward, when you wish to advance your body clock to match a hoped-for bedtime at your destination, Sara Mednick, PhD, a sleep researcher at the University of California, Irvine, explains in her book, The Power of the Downstate.
You can take the supplement before bedtime at your destination, or also ease into the new time zone days prior.
Example: If you fly from the West Coast to the East Coast and arrive at 10 p.m., your body clock thinks it’s 7 p.m. To prep for the change, take melatonin 30 minutes earlier each night, for five or six nights before the trip, Mednick suggests, to gradually shift your circadian rhythm so “it won’t be too surprised when you head to bed three hours ahead of schedule.”
Is it safe?
Melatonin is available over the counter in the United States, but a prescription is required in Australia, Japan, and Europe. Side effects, usually mild, can include headache, dizziness, agitation and even drowsiness.
The supplement “appears to be safe for most people,” according to the National Institutes of Health. Pregnant and breastfeeding women should avoid it, and people on blood thinner medications or who have epilepsy should consult a doctor first. If you take other medications or have underlying health conditions, get medical advice before taking melatonin, the Mayo Clinic advises. And don’t give it to kids without a recommendation from a healthcare professional.
Note that supplements are not regulated by the U.S. Food and Drug Administration, so look for those bearing a USP verification label, indicating the product has been tested with oversight from a nonprofit that ensures it contains what it says it does.
Bottom line: If jet lag isn’t a big problem for you, lean on natural daylight, dark hotel rooms at night, and other good sleep hygiene like lots of physical activity, limiting alcohol consumption, and avoiding caffeine beyond early afternoon. But if time-zone changes are your globetrotting nightmare, melatonin just might deserve a place in your travel bag.
This article does not constitute medical advice and is provided for informational purposes only. Consult your healthcare professional for any medical questions and before making any decisions.
Robert Roy Britt is an independent journalist covering physical health and mental wellness, and the author of “Make Sleep Your Superpower: A Guide to Greater Health, Happiness & Productivity.”