Jet lag, also known as time zone difference, occurs when we travel quickly to a place whose local time does not match the time followed by our internal clock. It is common after long flights that cross several time zones and can make it so that, even though the body asks for sleep, it is daytime at the destination; or that night arrives and sleep does not come.
It is not a disease or a sign that something is wrong. It is a temporary adaptation of the circadian rhythm, the system that helps organize periods of sleep and wakefulness, exposure to light, appetite, and part of our sense of energy throughout the day. The intensity and duration vary greatly among people, depending on the number of hours of difference, the direction of travel, the length of stay, and how well you rested before leaving.
What jet lag is and why it is so noticeable
The body does not change its schedule at the same moment the plane lands. Although the phone updates to the new time, the body maintains the signals of the place of origin for a while. That is why there can be intense sleepiness in the mid-afternoon, hunger at unusual times, or difficulty unwinding when night arrives.
Natural light is one of the most important signals for adjusting the internal clock. Meal times, physical activity, rest, and screen exposure also have an impact. When all those stimuli change suddenly, the body needs a few days to synchronize with the routine of the destination.
In general, the greater the number of time zones crossed, the more likely you are to notice the change. Eastbound travel tends to be more uncomfortable for some people because it involves moving the bedtime and wake-up time forward. Even so, there is no identical rule for everyone: age, stress, prior sleep quality, and the type of travel also count.
Frequent symptoms of jet lag
The best-known symptom is sleeping worse during the first days of the trip. It can be difficult to fall asleep at the local time, nighttime awakenings may occur, or it may be difficult to get up in the morning. It is also common to notice daytime fatigue, sleepiness at inconvenient times, lack of concentration, irritability, or reduced mental agility.
Some people notice digestive changes, such as reduced appetite, heavier digestion, constipation, or a feeling of hunger at unusual times. These changes are usually temporary and can be mixed with other travel factors: different meals, less hydration, alcohol, nerves, long hours sitting, or changes in physical activity.
If the discomfort is intense, lasts longer than expected, is accompanied by striking symptoms, or significantly interferes with daily life, it is advisable to consult a healthcare professional. This is especially important if a sleep disorder already exists, medication is taken regularly, or if you are traveling for work that requires driving, making important decisions, or maintaining sustained attention from the first day.
How to prepare before a long trip
Preparation begins before packing. Arriving at the trip with accumulated sleep debt usually makes adaptation even more difficult. During the previous days, try to maintain relatively regular schedules, rest enough, and avoid chaining short nights with especially demanding days.
If the time difference is significant and you have room to organize yourself, it can be useful to slightly move forward or backward your bedtime and wake-up time for a few days. There is no need to make drastic changes or turn it into an obligation. A gradual and realistic adjustment can make the jump to the new schedule somewhat less abrupt.
It also helps to plan the first day at the destination with reasonable expectations. If possible, avoid concentrating important meetings, very demanding excursions, or relevant decisions right after landing. Reserving some time to walk, eat calmly, and expose yourself to daylight can be more useful than trying to perform as if there had been no trip.
What to do during the flight
During the journey, try to gradually think about the schedule of the destination. If it will be night there, create an environment that facilitates rest: comfortable clothes, less light, headphones, or an eye mask if they are useful to you. If it will be daytime at the destination, prioritize staying awake with quiet activities, some movement, and light when possible.
Drinking water regularly helps to better handle the many hours of travel, especially because the cabin environment is usually dry. Alcohol can worsen the quality of rest and further alter sleep, so it is advisable to moderate it. Something similar happens with caffeine: it can be useful occasionally to stay awake, but taking it at the end of the day can make subsequent rest difficult.
Get up and move your legs when flight conditions allow. Short walks through the aisle, gently stretching ankles and calves, or changing posture help to avoid the feeling of stiffness after many hours sitting. If you have circulatory risk factors, pregnancy, personal history, or doubts about a long flight, consult a healthcare professional beforehand.
The first 48 hours at the destination
Once you arrive, the goal is to give the body clear signals of the new schedule. Exposing yourself to natural light during the day, going out for a walk, and doing gentle activity can help you stay awake until local night. There is no need to do intense exercise if you are exhausted: a quiet walk outdoors can already be a good option.
Try to eat at times similar to those of the destination, even if appetite does not fully accompany you at first. Choosing simple dishes, eating slowly, and not having overly heavy dinners can be more comfortable if the digestive system is also noticing the change in routine.
Long naps can make it harder to sleep at night. If fatigue is intense and you need to rest, a short nap can be preferable to sleeping several hours during the afternoon. At night, try to reduce intense light and screens near bedtime, especially if you notice they keep you more awake.
The basic habits of how to improve sleep naturally are also useful outside the home: a room as quiet and dark as possible, a pleasant temperature, a light dinner if it suits you better, and a simple routine to slow down before sleeping.
Melatonin and jet lag: what is advisable to keep in mind
Melatonin is a hormone that the body produces mainly when it gets dark and that participates in the regulation of the sleep-wake cycle. In the European Union, there is an authorized declaration indicating that melatonin contributes to alleviating the subjective feeling of jet lag when the corresponding conditions of use are met.
That does not mean that any supplement with melatonin is suitable for everyone or that it replaces the habits of adapting to the local schedule. The pattern, the amount, and the time of intake are important, and can vary depending on the product, the trip, and the personal situation. Taking it without considering the schedule of the destination is not always a good idea.
If you want to evaluate a supplement for a specific stage of travel, always review the full labeling, the recommended daily dose, and the warnings. BioSomnio incorporates melatonin along with other ingredients aimed at well-being and nighttime relaxation, but it is advisable to choose any supplement with criteria and use it according to its label.
Before using melatonin or any product intended for rest, ask for professional advice if you are pregnant or breastfeeding, if you take medication, if you have a chronic illness, if you suffer from a diagnosed sleep disorder, or if the trip is for a minor. It is also important to avoid mixing several products with a sedative effect or intended for sleep on your own.
If you want to know more about this ingredient and its role in nighttime routines, you can expand the information in 5 benefits of melatonin.
Errors that can prolong jet lag
One of the most frequent errors is trying to compensate for fatigue by sleeping all afternoon upon arrival. It can provide momentary relief, but it often delays nighttime sleep even further. Another is spending the whole day locked in the hotel or in spaces with little light, when going outside helps to mark the difference between day and night.
It is also advisable to avoid using alcohol as a way to “sleep better” on the plane or at the destination. Although it may cause drowsiness at first, it does not guarantee quality rest and can increase the feeling of fatigue the next day. Heavy dinners, caffeine late in the afternoon, and checking the phone in bed are other factors that can make adaptation difficult.
Finally, do not demand yourself to be completely adapted from the first day. Traveling already implies physical, emotional, and logistical changes. Maintaining a simple routine, exposing yourself to daylight, drinking water, eating with some regularity, and respecting rest is usually a more useful strategy than seeking immediate solutions.
When to consult about difficulties sleeping after a trip
Jet lag usually improves as the days pass and the body adapts to the local schedule. However, it is worth consulting if insomnia, extreme drowsiness, or fatigue last much longer than the trip, affect work or safety, or are accompanied by intense snoring, breathing pauses, marked anxiety, or significant changes in mood.
It is also advisable to ask for guidance if you notice that waking up in the early morning becomes a persistent problem, if sleep was already irregular before the trip, or if you need to frequently resort to sleep products. A professional can help assess the complete context and rule out other causes that are not directly related to the time change.
The goal is not to achieve a perfect trip or force yourself to sleep at a specific time from the first day. It is about accompanying the body during the transition, with simple and realistic measures, so that little by little it recognizes again when it is time to be awake and when it is time to rest.
Frequently asked questions
How long does jet lag last?
It can last a few days, although it depends on the crossed time zones, the direction of travel, prior rest, and the characteristics of each person.
Is traveling east or west worse?
Many people notice the trip east more because they have to move the sleep schedule forward. Even so, the experience is individual.
Does sleeping during the flight help avoid jet lag?
It can help if it coincides with the night of the destination. If it does not coincide, it does not always facilitate adaptation, and it is advisable to prioritize the local schedule once you arrive.
Can I take melatonin for jet lag?
Melatonin has an authorized declaration in the European Union to alleviate the subjective feeling of jet lag under specific conditions. Always review the labeling and consult a professional if you take medication or have any health condition.
Do naps worsen time zone difference?
Long naps can delay nighttime sleep. If you need to rest, a short nap is usually a more compatible alternative with adapting to the local schedule.