How To Avoid Jet Lag – The Complete Guide

image representing jet lagWith some careful planning, it’s possible to dramatically reduce how long you suffer from jet lag, and perhaps even avoid it entirely.

There are several things you can do before, during your flight and on arrival to help your internal body clock adjust to the new time zone.

Working out exactly what to do can get a little complicated, so I’m going to explain it in as much detail as possible in this article. Hopefully it will help you adapt much quicker the next time you travel.


  • Part 1: Cause and symptoms of jet lag
  • Part 2: Medical research 
  • Part 3: Different approaches to beating jet lag
  • Part 4: Comparison of jet lag calculators
  • Part 5: Light boxes and glasses
  • Part 6: How to minimize travel fatigue
  • Part 7: Can melatonin help?

Part 1: Cause and symptoms


Sleep follows a circadian rhythm, and is governed by your internal body clock. This clock is controlled by your internal biology, but is also affected by external factors, especially light.

If you cross time zones during your flight, then the new day/night timings won’t be aligned with your own body clock. This has a direct impact on your daytime alertness and ability to sleep during the new night.

But our internal body clock is remarkably stable and doesn’t like change. Numerous research trials have shown that most people can only force a change to their internal clock of between one and one and half hours every day.

Thus a five hour time zone change can take three to five days before you stop falling asleep over dinner or pacing your hotel room in the early hours of the morning.

One of the most important external factors controlling our internal body clock is the light-dark cycle. So controlling the amount and timing of your exposure to light can help adjust your sleep and waking-up timings.

image showing differences in jet lag adjustment when travelling east or westMost people’s daily body clocks tend to run a bit slow. If left alone it would drift later by a few minutes every day! But our daily sleep routine and exposure to light keeps it in check at 24 hours.

This natural drift helps to explain why it is generally quicker to shift your body clock when travelling West rather than East.

The rule of thumb is a 60 minute change per day after an East bound flight and 90 minutes change per day after a West bound flight.

Note that these time changes are only estimates, and some people may be able to change their body clocks by 2 hours per day.


Most travelers will have experienced the symptoms or effects of jet lag, the most common of which include:

  • An inability to go to sleep at the new night-time
  • Waking up too early in the morning
  • Feeling tired during the day
  • Lethargy
  • Sudden desire to sleep during the day
  • Loss of concentration
  • Irritability
  • Disorientation
  • Appetite changes
  • Changes to bathroom needs

It’s important to recognize the difference between travel fatigue and jet lag, especially as the overall symptoms may feel the same.

But general travel fatigue can be overcome relatively quickly, maybe after a rest and a night’s sleep. Jet lag tiredness, however, may well stay with you for much longer – until your body clock adjusts to the new time zone.

Later in the article we’ll also cover some actions you might consider to reduce travel fatigue.

Part 2: Medical research

There has been a lot medical research into jet lag, its causes and ways to overcome or minimize the effects.

One of the most comprehensive reports ‘How To Travel The World Without Jet Lag’ by Charmane, Eastman and Burgess reviewed many interesting research trials.

Their report also provides some detailed examples of the recommended approach to adjusting your body clock for a number of different long-haul flights.

The report really shows that shifting your time clock, with controlled exposure to strong light, is the best way to avoid jet lag. Or at least minimize the length of time you suffer from it. They also suggest that taking Melatonin can help.

The video below demonstrates how this technique works. It explains the basic principles of the circadian rhythm, and illustrates how you can adjust your body clock, providing one example based on flying East from Chicago to Paris.


Part 3: Different approaches to beating jet lag

Based on the Charmane, Eastman and Burgess review, there are three different approaches to dealing with the time zone changes:

  1. If away for a short period don’t try to adjust fully to the new time zone.
  2. Adjust to the new time zone after you arrive, by actively encouraging your body clock to change.
  3. Try to shift your body clock towards the new time zone before you travel.

Let’s take a closer look at each of these three approaches.

A) Don’t try to adjust to the new time zone

If the time change is less than three hours and it’s a short trip, then you may be better off not trying to adjust to the new time zone at all.

Instead just keep close to your normal sleep schedule. Or if there’s more than 3 hours time difference, then perhaps just change your sleep times slightly.

We know someone who traveled regularly from the UK to the East Coast of the USA on short business trips – a five hour time difference. His approach, which worked well for him, was only to adjust for two hours and not the full five.

So he would go to bed whilst in the USA around 9pm rather than midnight and get up between 4am and 5am. It’s probably easier to manage such a routine on business trips than on holidays though.

B) Adjust to the new time zone after arrival

Let’s admit it, this is what most of us do. But this can take up to a day for every hour time difference before you finally beat any jet lag.

And actually it might take much longer if you aren’t aware of the factors which influence your internal clock, for example exposure to strong light.

C) Make calculated adjustments before leaving

By adjusting your sleep times and exposure to light, you should be able to adjust your internal body clock towards the new time zone before you leave.

This will reduce the length of time you suffer from jet lag on arrival at your destination. Of course, it may be easier said than done, as changing your sleep routine could be difficult for personal, social or work reasons.

The attraction is that this approach might allow you to arrive in your destination virtually jet lag free.

This technique seems to be gaining more supporters, especially amongst business people and elite athletes. These people want to be able to perform at peak performance on arrival, regardless of the new time zone.

The next video shows another jet lag plan example, this time if travelling west from San Francisco to Beijing:

Part 4: Comparison of jet lag calculators

There are several online jet lag planners and calculators to choose from. They aim to provide guidance on light exposure to help adjust your body clock. A few provide advice on when to take Melatonin.

Some of the calculators are independent, and others are provided by manufactures supplying light boxes or special light glasses.

A word of caution though: Charmane, Eastman and Burgess also point out that some of the planners are not accurate enough and can result in the opposite effect.

By this they mean the advice could either slow the adjustment down or even make your clock adjust the wrong way, prolonging your jet lag.

This would obviously be a problem, so it’s important to use an accurate planner, something which our research below will help you find.

Most of the advice from websites and online calculators is really based on the average person. But there are a couple of important points to consider:

  • If the time zone change is greater than about 8 hours then your body clock could either advance or delay to get you back to the new time. This is more likely to happen if flying east, due to differences in the speed that your clock can change as discussed above. There is a risk that actions you take could end up fighting the natural tendency of your body clock.
  • People whose natural sleep cycle is much later (real night owls) or much earlier (very early birds) might also find it easier to start adjusting their body clocks in different directions.

If these apply to you, or you find the ‘standard’ plan doesn’t work for you, then you may need to read the Charmane, Eastman and Burgess report more closely to ensure the plan is the best one for you.

Making a note of what appears to be happening, for example the time you feel most sleepy during the day, might help you decide which way your body clock is moving.

With some careful planning, you should then be able to change your actions to help rather than hinder the adjustment process.

Comparison of programs

We compared five different online calculators against two of the trips described by Charmane, Eastman and Burgess.

Their advice for these two trips is based on very accurate calculations, so they are good points to compare the calculators with.

The table below shows their advice for a flight leaving Chicago at 4.30pm (Chicago time) and arriving in Paris at 8.30am (Paris time) the next morning. Paris is 7 hours ahead of Chicago, so it feels as if you are arriving at 1.30 in the morning.

DayAvoid light (Paris local time)Seek light (Paris local time)
Arrival day8.30am to 12pm12pm to 4pm
Day 28am to 11am11am to 3pm
Day 38am to 10am10am to 2pm
Day 48am to 9am9am to 1pm

The image below shows an example of what their advice says you should do on day 2 in Paris:

jet lag plan for chicago to paris

The second trip we looked at was between San Francisco and Beijing. In this case we looked at the option of starting to adjust your sleep times in San Francisco during the three days before you head off to the airport.

1) Rooster

Rating: 5 out of 5

jetlagrooster screenshot

We found Rooster’s online option very easy to use. It also allowed you to select when you want to start the adjustment – before, during the flight or on arrival.

It appears to be very close to the research based solution. For the Chicago to Paris flight, the Rooster recommended times to avoid and seek light were almost the same as in the table above.

For the San Francisco to Beijing flight, there were a couple of small differences in timings compared to the Charmane, Eastman and Burgess solution.

But overall the calculations for the best times to seek and avoid light were very close and the differences didn’t seem to be major.

In our comparisons we found this was the most accurate jet lag planner, and so is our recommended online calculator.

Find out more at >>

2) Lumie

Rating: 4 out of 5

photo of a lumie jet lag plan from chicago to parisLumie, a manufacturer of light therapy products, also have an online jet lag calculator. It’s easy to use with good graphics and it appeared to give reasonable advice.

But it only gave advice for three days, regardless of the number of time zone changes. Like other calculators it assumes you can change your body clock faster than researchers say is normal.

Furthermore, it doesn’t allow you to select the option of starting your adjustment before you leave. Overall it’s a relatively easy and reliable calculator, though we still don’t think it’s as good as Rooster.

Find out more at >>

3) British Airways Jet Lag Advisor

Rating: 3 out of 5

screenshot of the british airways jetlag calculator
The British Airways jet lag calculator only gives you two days worth of advice, regardless of the number of time zones crossed.

The Day 1 recommendation is okay, but Day 2 seems to assume that you have adjusted your body clock by much more than the 1 hour per day.

The advice for the San Francisco to Beijing flight wasn’t much better and again only covered 2 days.

We aren’t convinced this advice is going to make much difference to you overcoming jet lag more quickly.

Find out more from >>

4) Entrain App

Rating: 2 out of 5

image of the entrain app jet lag screen

The Entrain jet lag App has had publicity in the press recently, so we downloaded it onto an IPad to test its accuracy. We found it rather confusing to use, as you have to go through a number of different steps to get an answer.

It suggested exposure to light about an hour and a half earlier in the day than the other calculators, which might actually prolong your jet lag. After Day 3 it suggested exposure to light when you should still be asleep.

For the San Francisco to Beijing flight it appeared to say that there was only a 1 hour time zone difference. On a second try it said there was a 5 hour difference, both of which aren’t correct.

So as you can imagine, we weren’t very impressed with the App. Until the the accuracy is improved, we wouldn’t recommend using it.

You can find the Entrain jet lag app by searching on the apple store.

5) Prokerala

Rating: 2 out of 5

The Prokerala travel site’s jet lag calculator is easy to use, but again only gave two days worth of advice. For the first day it suggests seeking bright light at 9.30am, which is too early.

For the second day it also recommends exposure to strong light when you should be trying to sleep.

So we don’t recommend using their calculator, especially if you’re crossing multiple time zones and need a more thorough plan.

For more information visit >>

Part 5: Light boxes and glasses

Research suggests that exposure to strong light at the right time is the key to shifting your body clock. Many sportspeople are aware of this; even the Los Angeles Dodgers used light to avoid jet lag when playing in Australia.

But not everyone has the luxury of spending time in the sun whenever they feel. Especially if you’re on a business trip. Fortunately, there are light boxes and light glasses which you can use indoors as a replacement.

So let’s take a look at the different kinds of products which may also help you beat jet lag when travelling.

Light Boxes

A number of companies offer light boxes, both fixed and portable. Some are designed primarily to help people with Seasonal Affective Disorder (SAD). But they can also be used to help overcome jet lag by providing exposure to strong light.

It’s worth remembering that exposure to strong sunlight is the best option. But these devices could be useful for times when it’s either dark outside or you’re indoors working for example.

Some of the top-range light boxes are understandably quite expensive, but there are cheaper options, especially in the portable market.


Lumie produce a number of light boxes, and even supply them to the UK National Health Service.

Their website suggests that a Zest portable light box could be used to overcome jet lag, and we’ve seen some good reviews for the product.

woman using a lumie zest light box


Biobrite also manufacture a number of different light boxes, ranging from subtle desk lamps to larger panels of light.

They even say they have a light visor which is used by NASA astronauts to minimize jet lag!

woman using a biobrite light box


This UK based company focuses on sleep disorders and has some competitively priced portable light boxes, specifically created to help overcome jet lag.

They state that because their light box uses LEDs, it greatly decreases the amount of time you actually need to spend in front of it.


Light glasses

There are also companies who manufacture special light glasses to help overcome jet lag.

Again this is all about controlling your exposure to light, and the right kind of light. Two examples are shown below.

Re-timer glasses

These glasses, and the claims by the manufacturer, have received quite a lot of publicity in the press.

They are designed to be worn when you should be seeking strong light. They use 100% UV-free green light, which helps your body to adjust its body clock.

re-timer glasses


The Luminette visor light glasses are designed to help with the winter blues, but can also be used to help you get strong light when travelling.

The manufacturer claims that the more targeted effect of the light onto the eyes helps reduce the time you actually need to use them when compared to a light box.

luminette light glasses

Part 6: How to minimize travel fatigue

If flying long distance you may also suffer from travel fatigue, even if there is no significant time zone change. A typical example is flying from the USA to South America.

But there are things you can do before you travel to help with travel fatigue.

These actions probably won’t help you change your body clock. But they will help you feel more rested and better able to deal with the dreaded jet lag symptoms.

Steps to take before you travel

  • Try to ensure you are well rested in the days leading up to your departure date. If you work yourself into the ground and travel when exhausted, you may find it takes longer to overcome travel fatigue, as well as adjust for jet lag. It probably won’t really help to tire yourself out so much just so you can sleep on the plane.
  • Try to do some exercise the day before traveling, or in the morning if traveling later on in the day. But perhaps avoid strenuous exercise close to the flight time if you plan to sleep on the plane.
  • You might want to limit the amount of alcohol you drink before flying. Alcohol can help you fall asleep quicker, but then disrupts your quality of sleep. So you may be more tired when you arrive, even if you manage to knock yourself out initially.

Things that help while on the journey

  • Drink plenty of liquids such as liquid and juices (not alcohol though!). It’s easy to get dehydrated on a plane due to the change in air pressure and humidity. Buy a large bottle of water once you pass through security. You can then take this on board, instead of relying on the complimentary (or expensive) drinks, which may not be enough to keep you well hydrated.
  • Bring accessories to help you sleep better; you might find that a good sleep mask, some ear plugs and a cozy warm jumper all help you relax.
  • If you have a long stopover, take the opportunity to walk around and get the blood moving in your body. If there are facilities like a shower, then freshening up may help you sleep on the next leg of the journey.
  • If you decide to use sleeping pills, remember that many may leave you feeling groggy when you wake up. If you can sleep naturally, it will benefit you when you arrive.

Part 7: Can melatonin help with jet lag?

melatonin pills for jet lagMelatonin is one of those sleeping pills which receive a lot of attention because they are more ‘natural’ than most others.

In a previous article we discussed how melatonin isn’t very useful for insomnia, but can help you avoid jet lag.

Charmane, Eastman and Burgess explain how Melatonin can help jet lag in two possible ways:

  • Taking a larger dose of 3mg before bedtime for the first few nights following an East going flight. In this case it’s really helping you to go to sleep when you body is saying it’s time to be awake. Taken at this time it’s probably acting both as a sedative as well as helping to change your body clock.
  • Taking a smaller dose of 0.5mg two to three hours before you’re due to go to sleep in the new time zone. This is about the time your body would normally start producing Melatonin as part of the Circadian rhythm. Thus taking Melatonin at this time is aimed at helping to move your body clock to the new time zone. Note though taking a larger dose at this time doesn’t seem to be any more effective.

Shining a light on the back of the knee – miracle or myth?

As is often the case there are various bizarre theories and urban myths about how to avoid jet lag. These include ideas such as shining a light in the back of your knee and changing your diet and eating times.

None of these, however, appear to be supported by robust research. So I’m sorry to say that despite what you may have heard, half an hour with a torch on your knee isn’t going to help!


Whilst there is no instant cure for jet lag, there are plenty of things you can do to reduce how long you suffer from it.

The key to beating jet lag is changing your body clock to match the new time zone. This requires a good understanding of how exposure to light at different times can affect your body clock.

There are a number of online calculators which can help you design an effective jet lag plan. We recommended the Rooster calculator as a good option.

On arrival at an exciting new destination it’s difficult to resist the temptation to start exploring. But, armed with your plan, you can take some measures to help your body clock without spoiling your trip.

The best news though is that by making some adjustments to your body clock before departure, it may be possible to arrive jet lag free.

I’d be very interested to hear from anyone who has used a jet lag program and whether they found it useful. And if you have any other interesting tips or techniques for dealing with jet lag, please do share them below so other readers can benefit from your experience.

6 CommentsLeave a comment

  • I have this. It’s a pain in the backside because people say you’re lazy when you turn up for work late, and when you tell them you didn’t get to sleep until 3 am they tell you to go to bed earlier. All that happens if you do that is you lie in bed for hours. You can sort of lie to your body clock about what time it is, though, by controlling light and melatonin levels. So it’s not all bad. It does work the other way, too. People with Advanced Sleep Phase always get told they’re a lightweight because they don’t want to go out with their friends all night because they’re tired by 8pm. It is difficult, though. Tell people you need glasses and they’re all sympathetic. Tell em you need to sleep in the mornings and they reckon it must be some lifestyle inadequacy. *sigh* Get your friends to have a look at And above all, thanks for being sympathetic. We don’t like being called lazy, nor do we like wasting half of the weekend catching up on sleep. I don’t think my lark friends would like me ringing them up at 2 am telling them they’re lazy for going to bed so early! :-D

    • Hi John
      Thank you for your comment. I can understand the frustration of your timings not being in line with people around you and your work life. I’m assuming you travel a lot for work? Do you regularly have to try and adjust your body clock?

      You’re right in that sleep schedules can be very different between people. Teenagers are often berated for staying up late and getting up late, when it’s actually quite normal for teens to experience delayed sleep phase syndrome. And not everyone is able to stay up late and party!


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