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    Jet lag: causes, treatments & tips

    On this page
    1. What is jet lag?
    2. How long does jet lag last?
    3. What is the cause of jet lag?
    4. How to avoid jet lag
    5. Treatment for jet lag
    6. More travel advice

    Written by Dr Kieran Seyan

    Man asleep in airport

    There’s some curiosity around the phenomenon of jet lag, what are the symptoms, how best to treat it and how to get over it quickly. You might also be wondering is it better for jet lag to travel east rather than west? Or vice versa? Or does it matter at all? In this article we have all the travel advice you need.

    We surveyed* 500 Brits to explore the effects of jet lag and how the severity of symptoms varies, and how we typically manage them. We also teamed with Dr Kieran Seyan to find out their top tips for beating jet lag. 

    What is jet lag?

    Jet lag is when your normal sleep pattern is disturbed after a long flight. Each of our body functions follow a circadian rhythm, which serves as our personal internal clock. This is all powered by a section of the brain called the hypothalamus.

    This internal master clock that we all possess produces a hormone called melatonin when it gets dark, making us drowsy and ready for bed. Flying to a new time zone causes our internal clock to go out of sync with the time at our destination and then the body has to re-establish a natural rhythm. This is where jet lag comes in.


    Symptoms of jet lag usually last for a few days while your body physically adjusts to the new time zone before settling into the patterns of your new time zone.

    Jet lag symptoms include:

    • Finding it hard to sleep at night
    • Struggling to wake up in the morning
    • Feeling tired and exhausted
    • Struggling to stay awake during the day
    • Poor overall quality of sleep
    • Memory and concentration problems
    • Nausea and appetite changes
    • Indigestion
    • Constipation

    A staggering 74% of respondents revealed that they experienced symptoms of fatigue after a flight while 32% experienced headaches and 31% admit to feeling dehydrated. 1 In 4 say muscle aches are a common effect post-flight, while 16% feel nauseous.  

    How long does jet lag last?

    Jet lag symptoms usually occur a day or two after travelling. They tend to last for a few days and may be worse depending on the distance you’ve travelled, for example across two different time zones. 

    Once your body has adjusted to your new time zone and routine your symptoms should improve and disappear. 

    According to the study, 51% say that jet lag symptoms typically last up to 3 days, while just 32% experienced symptoms for less than 24 hours. 

    Do you get more jet lag travelling east than west?

    Science has an answer for this one, and that answer is yes, it is more difficult for a human body to travel east than west. A study published in 2016 crunched the numbers on why travelling east is worse for jet lag. In short, your body’s natural rhythm follows a 24.5-hour day, slightly longer than the standard 24-hour sun-up, sun-down rhythm. That means that if you’re travelling east over many time zones, you’ll ‘lose’ additional time.

    In a way, you’re travelling forwards in terms of hours and days, arriving ahead of yourself which requires your body to be ‘advanced’. For example if you: 

    • Take off in London at 7am on Monday and fly for 11 hours to Tokyo, which is eight hours ahead.
    • On London time, you land at 6pm. Your body is ready for dinner and a night’s sleep.
    • On Tokyo time, you took off at 3pm on Monday and arrived at 2am on Tuesday.
    • Arriving in the middle of the night effectively means you miss a night’s sleep – you’re jumping ahead to the next day.

    What is the cause of jet lag?

    Jet lag is caused by a few different things including: 

    1. Disruption of your circadian rhythm - Travelling across multiple time zones puts your internal clock (circadian rhythm) out of sync.
    2. Influence of sunlight - Light affects the hormone melatonin which helps cells in the body work and helps us sleep. Too much or too little light can alter the quality of sleep we get. 
    3. Airplane cabin pressure and atmosphere - The plane environment has been thought to contribute to jet lag symptoms. 

    Need jet lag treatment?

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    How to avoid jet lag

    Given time, your body will deal with jet lag naturally. However, there are some other natural remedies, outlined below, that you can try before trying jet lag tablets.

    The survey revealed that 58% of Brits try to stay hydrated during a flight in order to minimise the effects of jet lag. However, just 40% adjust their sleep schedule before the flight, and only 28% seek exposure to natural sunlight upon arrival.

    Planning your trip

    • Select flight times strategically and pick a flight that allows you to arrive in the early evening, ensuring you get a good night’s sleep straight away
    • Plan extra days if possible, and get to your destination a few days early so you can acclimatise before any big event you’ll be attending
    • Anticipate the change – if you’re flying eastward, get up earlier for a few days prior to your departure; If you’re flying westward, do the opposite and stay awake longer

    Five popular holiday destinations flying east from London 

    1. Bangkok, Thailand

    Known for its vibrant street life, ornate temples, and bustling markets, Bangkok is a popular holiday destination for travellers of all ages. 

    2. Tokyo, Japan 

    A city that blends tradition with modern technology, Tokyo offers a unique cultural experience. From futuristic skyscrapers to historic temples, immerse yourself in the vibrant atmosphere of this bustling metropolis. 

    3. Sydney, Australia 

    From the long list of activities, beautiful weather and the stunning beaches, Sydney is a desirable destination for travellers heading east from London. The city's vibrant arts scene, diverse culinary offerings, and beautiful coastal landscapes make it a must-visit place. 

    4. Dubai, United Arab Emirates 

    Known for its impressive skyline, luxurious shopping malls, and world-class resorts, Dubai is a popular destination for those looking to indulge in lavish experiences, explore traditional souks, and enjoy the city's glamorous ambiance. 

    5. Cape Town, South Africa 

    With its stunning natural beauty, including Table Mountain and picturesque coastlines, Cape Town is a captivating destination for visitors to enjoy a blend of outdoor adventures, vibrant nightlife, and rich cultural heritage. 

    Five popular holiday destinations flying west from London 

    1. New York City, United States 

    New York, one of the most famous cities in the world, offers a blend of culture, entertainment with vibrant neighbourhoods like Brookyln and a host of famous landmarks like Times Square, Central Park, and the Statue of Liberty. 

    2. Los Angeles, United States 

    The entertainment capital of the world, Los Angeles attracts visitors from all walks of life. With its sunny beaches, Hollywood glamour, and iconic attractions like the Walk of Fame and Universal Studios. 

    3. Vancouver, Canada 

    Situated between the Pacific Ocean and the mountains, Vancouver offers a combination of natural beauty and urban sophistication, where travellers can enjoy outdoor activities on the doorstep of this vibrant Canadian city. 

    4. San Francisco, United States 

    Home to the Golden Gate Bridge and Alcatraz Island, San Francisco is a popular destination for those looking for great nightlife, charming neighbourhoods and delicious cuisine. 

    5. Cancún, Mexico 

    Located on the Caribbean coast, Cancún is renowned for its stunning beaches, crystal-clear waters, and vibrant nightlife.  

    On the plane

    • Set your watch to the destination’s time zone as soon as you’re on the plane
    • Sleep on the plane if you’re travelling eastward
    • Don’t drink alcohol or caffeine on the flight, as both will make things worse

    On arrival

    • If bedtime is too far away and you just have to sleep, take a power nap of no more than 20 minutes – make sure you set an alarm so you don’t sleep for too long
    • Go outside during the day – natural light will help your body clock adjust

    Jet lag is extremely common when embarking on long haul trips. However, according to Dr Kieran Seyan there are several ways that we can manage these side effects.  

    “Gradually shifting your sleep and wake times several days before your trip allows your body to adjust to the new time zone more smoothly and be more prepared for a drastic change to or circadian rhythm.  

    Drink plenty of water before, during, and after your flight as dehydration can significantly worsen the symptoms of jet lag. As mentioned, avoid alcohol and caffeine as they can disrupt your sleep patterns and make it more difficult for your body to adjust to the new time zone.  

    Spending time in natural sunlight is also encouraged when arriving at your destination. Sunlight will help to regulate your body's internal clock as well as naturally increasing your energy levels during the day. Staying active and engaging in light physical activity can help reset your body clock and combat excess fatigue."

    If you are very worried about dealing with jet lag, tablets are available to help you get over it faster. They should not be taken for more than a few days, and should never be used as a cure for insomnia when you aren’t actually travelling.

    Treatment for jet lag

    There are three simple steps to get jet lag treatment:

    • Complete an online consultation (it’s short and takes about 5 minutes)
    • A clinician will assess your suitability, and if you’re eligible will prescribe a treatment
    • Choose collection or delivery

    More travel advice

    Online Doctor can help you prepare for your next trip with malaria treatment and prevention tips. If you’re pregnant we have everything you need to know about travelling safely.


    Onepulse conducted a survey on behalf of Lloyds Pharmacy Online Doctor and surveyed 500 male and female respondents in the UK between 05/05/23 and 06/05/23. They were then given three questions of multiple choice to describe their experience with jet lag in relation to a number of different factors.

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