Insomnia, daytime tiredness and gastrointestinal problems are all symptoms of jet lag. But what exactly causes these symptoms? And, if it’s possible, how can you cure jet lag?

Here at Omio, we wanted to get to the bottom of this unpleasant state we call jet lag and got in touch with two experts on the subject.

Click here to jump to what is jet lag or how to avoid jet lag.

We consulted with Dr. Eastman from the Biological Rhythms Research lab at Rush University Medical Centre in Chicago and with Jay Olson, M.Sc. Psychiatry Dept. at McGill University, who created a website called The website lets people enter their trip details and get their very own jet lag battle plan, which may help them to reduce the symptoms of jet lag.

What is jet lag?


Jet lag is a combination of symptoms that occur when our internal body clock is disturbed. Each of us has an internal body clock which is a group of 20,000 nerve cells located in an area of our brain, just above the optic nerves behind the eyes.

When we fly across several time zones, travelling east or west, we disrupt this group of cells, as they need time to adjust to the new time zone and to the different hours of daylight. This may lead to typical jet lag symptoms such as insomnia.

Dr. Eastman defines the occurrence of jet lag as “…after you travel to another time zone, your body and your internal biological clock remain on your home time zone. Then, gradually, by about an hour a day (sometimes much more or much less) your clock resets or shifts to the new time zone. Jet lag only happens when you cross time zones, going east or west, but not when travelling north or south.  In that case you might experience travel fatigue, but that is not jet lag.”


How to Avoid Jet Lag


Prepare a pre-flight sleep schedule

Following a sleep schedule with light and darkness exposure at specific times prior to your flight is a good way to reduce the symptoms of jet lag, but it’s tricky to know exactly when to get light and when to avoid bright light or be in the dark (sleeping).

Organising a sleep schedule before your departure will give your internal clock a kickstart on the impending time zone change. Dr. Eastman provided us with a pre-flight schedule example commencing four nights before departure from London to New York.

Four nights before flying –  if you usually sleep from midnight to 7 am, then get some bright light from 10 pm to midnight. The light can be intermittent, so you can take breaks from the lightbox. Stay indoors for a few hours after waking. If you have to go out, use dark sunglasses. Those that are dark and are also called “blue blockers” are good.

Three nights before flying – the next night go to bed 1 hour later, at 1 am, after getting bright light from 11 pm to 1 am. Try to sleep until 8 am or later, and then stay indoors for a few hours.

Two nights before flying – the following night go to bed at 2 am, after getting bright light from midnight to 2 am, and try to sleep until 9 am or later. Avoid bright light for a few hours after that.

One night before flying – the next night go to bed at 3 am, after getting some bright light from 1 am to 3 am, and try to sleep until 10 am or later. If you are sleeping from 3 am to 10 am in London, that’s the equivalent of 10 pm to 5 am in New York.

Night after flying – after the flight you will probably be able to sleep from 11 pm to 6 am in New York. You will wake up a little later naturally during the next few days. If you wake up before 6 am on the first few nights, don’t lie in bed if you really can’t sleep it’s better to get up and do something in dim lighting.”


Timed light and dark exposure.

jet lag

The key to avoiding symptoms of jet lag is timed light and dark exposure. Calculating the best time to get dark or light exposure can be tricky because you have to consider the number of time zones you’ll be crossing and what time it is at your destination.

Jay Olsen further notes: “Calculating when to get light exposure is challenging. I created Jet Lag Rooster to help travellers know when they should get bright light exposure and when they should avoid light (e.g., wearing sunglasses or staying indoors).”

Besides knowing when to get light exposure and when to avoid light, there are still some other things you can do to help with post-flight travel fatigue, as Jay Olson explains further;

Upon arriving at the destination, travellers can still get light exposure at the right times in order to reduce jet lag. Beyond this, to reduce general fatigue, we recommend that travellers drink a lot of water, eat fruit, take a shower, and have a brief nap if needed.”


What are some other ways to avoid jet lag?


We asked our in-house travel experts at Omio about what they think is the best way to avoid jet lag before taking off.

Catherine: If you prefer to spend your flight asleep it may be best to turn off that in-flight movie and pull a sleep mask over your eyes. The light exposure from the screen will only keep you awake longer as the brightness can mess with your internal body clock.

Catriona: Before jetting off, put together a small flying kit which you can bring on in your hand luggage with earplugs, a sleep mask, a neck pillow and whatever else may help ease the long flight time.

Hannah: If you want to freshen up before you land, bring some face wipes and a small tub of moisturiser onboard with you. It will help kickstart your jet lag recovery.

Sebastian: I like to make sure everything is prepared for my trip before I take off, like transport from the airport to my accommodation, especially if I’m travelling with my family.


Are there any quick remedies for jet lag post-flight?

Hannah: This may sound strange, but I found wearing sunglasses indoors helps me get over jet lag a lot sooner. I believe this comes down to the smaller amount of light. Plus it makes me feel like a superstar.

Catherine: If I’m taking a longer trip abroad I like to spend one day catching up on my sleep after a long flight. This way I can enjoy the rest of trip without feeling really tired and groggy!

Sebastian: Water, water, water! It’s the best thing for getting rid of that drowsiness that comes with flying long-distance!


So is jet lag avoidable?

Experiencing jet lag may be unavoidable if you’re flying across three or more time zones, but the symptoms of jet lag can be eased by using the right preventative measures.

Have you experienced jet lag? Let us know below in the comments section your best jet lag remedy or pre-flight tip.


Looking for a budget break? Why not check out our top ten tips for finding cheap flights.  


Dr. Eastman creates personalised no-jet-lag schedules. If you would like to get advice, please contact Dr. Eastman at least 3 weeks before your flight. E-mail: [email protected].

Catherine Munnelly

Born and bred in Dublin, Catherine left the Emerald Isle in pursuit of exploration. Her hobbies include spending countless hours planning her next trip, travel blogging and Google deep diving.
Catherine Munnelly