Can apps and hacks really prevent jet lag?

Mint

23-07-2025

The body's internal clock gets out of sync with the local time when we cross time zones, leading to jet lag.
This wasn't the birthday greeting I had in mind: a 6 a.m. alarm blaring in my ear.
I had taken the day off for a milestone birthday (let's not put a number on it) but here I was, bleary-eyed and grumpy, thanks to a jet-lag app I was testing for a family trip to Greece the following day.
Sleeping in is one of my favorite pastimes. But when a friend traveled to India on a business trip with no jet lag after using an app, I figured it was worth a try.
Jet lag is temporary but real. When we cross time zones, our circadian rhythm—the body's internal clock, which regulates just about every function in our bodies—gets out of sync with the local time. That can lead to fatigue, insomnia, headaches and brain fog.
Though it poses no serious health risks, jet lag can hamper, or ruin, a vacation or business trip. So hacks from glasses to light boxes to supplements abound.
Jet lag is worse heading east than west. Our internal clocks adjust about an hour a day, so transitioning to Greek time, a seven-hour difference, can take a week. Not ideal when your trip is only eight days.
But I wasn't the only body clock under consideration. I was traveling with a teenager who regularly stays up past 1 a.m. and a tween who can't sleep past 8 a.m. My husband, who wakes up an hour earlier than me, tried the app, too.
Age differences and jet lag aren't well studied, but Dr. Jamie Zeitzer, professor of psychiatry and behavioral sciences at Stanford University School of Medicine, says young kids often adjust faster. Teens may, too, for a different reason. 'They're just so tired they can sleep whenever," he says.
There are a number of apps that try to tackle jet lag. For example, StopJetLag gives light, sleep, meal and activity advice starting three days before travel. It costs $78 a trip.
Flykitt, which is $99 for the first trip, includes five supplements, blue-light blocking glasses and sleep and eating advice. It revolves around the principle that pressure changes during flights can trigger inflammation for several days.
I settled on an app called Timeshifter because the first trip was free and it focused on light exposure, with optional melatonin and caffeine—two tools I already use.
Mickey Beyer-Clausen, the CEO of Timeshifter, and chief scientist Steven Lockley say the app shifts your circadian clock three to four hours a day. So on a trip from New York to Athens with a seven-hour difference, I should be able to shift in 1.5 to two days.
Preparations for the trip started a few days in advance. I logged my sleep habits (11 p.m. to 7 a.m.) and enthusiastically signed on to using caffeine and melatonin.
Day one was easy. It was pretty much my normal schedule but then came an alert: Avoid light from 9 to 10 p.m. And ruminate over midlife in the dark? Instead, I chose to read on my Kindle. Bad call. According to Timeshifter it would have been better to watch TV or read a book in a dimly lighted room wearing sunglasses.
The next day, my birthday, started with a 6 a.m. wake-up and an unusually early bed time: 9 p.m. When a friend showed up with a surprise cake just before then we were thrown off. The next day was worse: a 5 a.m. wake-up for me, 4 a.m. for my husband.
We persevered. I only had two hours for caffeine and guzzled it. By the time my 17-year-old son woke hours later, I snapped at him to finish packing. He barked back, 'What's the point of this app if you're just jet lagged before the trip? Just be tired and you'll sleep on the plane."
Did he have a point?
Once on the plane, I was exhausted but the app didn't have me sleeping for another two hours. I dozed for maybe an hour. The rest was restless half-sleep with constant peeks at the flight map and time. That's fine, says Lockley, who formerly worked as a sleep researcher at Harvard Medical School.
More important than sleeping, is avoiding light. 'It's not about sleep, it's about the circadian clock," he says. 'It's the dark that matters," he adds.
Health columnist Sumathi Reddy with her family on a trip to Greece.
We landed in Athens at 6 a.m., caught a connecting flight, and by 2 p.m. were on Milos. The Timeshifter alerts popping up were still on New York Time so we ignored them (a temporary kink Beyer-Clausen says was fixed). As tempted as we were to nap, the Aegean Sea lured us in for a swim.
Greeks eat late, so dinner was at 8 p.m. Timeshifter said bedtime was 11 p.m. By the time we got back at 10 p.m. I could barely keep my eyes open. The app called for a 7 a.m. wake-up but I was on vacation! We set the alarm for 9. (TimeShifter says it's adding a feature for a vacation sleeping pattern.)
We all slept through the night. From there, the plan was simple: sunshine and caffeine in the morning; limited light before bed; and bed time pushing 11 p.m.
When the shift to New York began a few days later, calling for limited light over breakfast, I decided to mostly ignore the recommendations. A four-hour delay on the flight home threw everything off anyway.
I paid a price for the neglect: The workweek was a blur of nodding off at my desk, falling asleep by 9 p.m., and waking up before dawn.
So was the pre-trip prep—early morning birthday wake-up and all—worth it? I think so. I may have transformed into a grumpy, morning person but the payoff was a postcard-perfect Greek island vacation.
I'm ready to do it again in September for a girl's trip to Spain.
Write to Sumathi Reddy at [e-mail]