Jet lag happens when your internal body clock is still set to your old time zone while your environment has already moved on, leaving you tired at the wrong times and wide awake at others. It resolves on its own eventually, but a few deliberate steps before and after you travel may shorten the adjustment time.
Who This Is For
This is for you if you’re traveling across multiple time zones and want to minimize how long it takes your body to adjust, or if you’re dealing with jet lag right now and need practical steps to speed up recovery.
Quick Fix / Summary
- Jet lag is a mismatch between your internal body clock and your new local time
- Traveling east is generally harder to adjust to than traveling west
- Light exposure is the main tool for shifting your body clock
- Shifting your schedule a little before you travel may reduce adjustment time
- As a rough rule, the CDC puts the average rate of adaptation at about 1 hour per day after eastward travel and 1.5 hours per day after westward travel, so expect roughly a day per time zone going east and somewhat less going west
- Low-dose melatonin, timed correctly, may help shift your clock (the CDC Yellow Book lists 0.5-1 mg as often sufficient; check with a clinician first if you take other medications)
Why This Happens
Your body runs on a roughly 24-hour internal clock (circadian rhythm) that’s set primarily by light exposure. When you fly across time zones faster than your body can naturally adjust, your internal clock stays synced to your departure time zone for days, even though the sun outside says otherwise. This mismatch is what causes the fatigue, poor sleep, and daytime grogginess associated with jet lag.
Flying east is typically harder than flying west because it requires your body to shift its clock forward (a shorter day). The CDC Yellow Book explains that for most people it is easier to delay than to advance the circadian rhythm, because the average period of the intrinsic rhythm is slightly longer than 24 hours. Your natural chronotype may also play a role here: night owls may find westward travel easier and eastward flights harder, and early birds the reverse, though this is less well established.
How to Fix It
1. Start Shifting Before You Fly
The CDC Yellow Book advises adjusting your sleep time to more closely match the destination’s sleep period for a few days before the trip, and gives 1 hour per day over the 2-3 days before departure as an example, shifting earlier for eastbound flights and later for westbound ones. Even a partial head start may reduce the adjustment needed once you land.
2. Use Light Strategically
Light is the strongest signal your body clock responds to: per the CDC Yellow Book, bright light in the morning generally promotes earlier sleep and wake times, while evening light promotes later ones. Seek bright light (ideally outdoors) at times that push your schedule toward your destination, and avoid bright light, especially screens, when you want to be shifting your clock the other way. The right timing depends on direction of travel, so a jet lag app or your destination’s sunrise/sunset time is worth checking.
3. Set Your Watch Early
Switch your phone and mindset to destination time as soon as you board. Eating and sleeping according to the new time zone, even on the plane, may help your body start adjusting before you land.
4. Consider Low-Dose Melatonin
Taken at the right time relative to your destination’s evening, low-dose melatonin may help nudge your body clock into sync faster. The CDC Yellow Book says 0.5-1 mg is often sufficient to produce a circadian shift, and that it is less effective when taken while your own melatonin is already high (body-clock time of roughly 12-5 a.m.). Check with a doctor or pharmacist first if you take other medications or have a health condition. See the best melatonin supplements and correct dosing for specifics, timing matters more than dose here too.
5. Get Outside on Arrival
Daylight after landing is one of the main cues your body clock uses to reset. A walk outside, even if you’re exhausted, may help more than staying in a dark hotel room. If the first night in the new bed is the problem rather than the time zone, see can’t sleep the first night in a new place.
6. Avoid Long Naps on Arrival Day
A long nap can undo the adjustment you’re trying to make. If you need rest, keep it short, see how to nap without ruining your sleep for the right length and timing.
Practical Tips That Actually Help
- If you’re flying east → seek morning light at your destination and avoid it in the evening
- If you’re flying west → seek evening light and avoid early morning light
- If you land exhausted → get outside briefly rather than immediately sleeping
- If you must nap → keep it to about 20-30 minutes, since the CDC notes longer naps may interfere with nighttime sleep
- Stay hydrated and go easy on alcohol during the flight, both affect sleep quality and adjustment speed
Common Mistakes to Avoid
- Staying on home time zone “just for this trip”, it may be reasonable for a very short trip, but it can leave you out of sync on longer ones
- Taking melatonin at a random time, timing relative to your destination matters more than just taking it before any bedtime
- Napping for hours on arrival day, it feels good in the moment but slows down the adjustment
- Ignoring light exposure, it’s a powerful, free tool and often overlooked in favor of supplements
Related Reading
- Shift Work Sleep Disorder: How to Sleep Better on a Night Shift Schedule
- Why Does My Brain Not Shut Off at Night? (Causes + Fixes)
FAQ
Why is jet lag worse when flying east than flying west?
Flying east requires your body to shift its internal clock forward, which is harder for most people than shifting it backward when flying west, because the body clock’s natural period is slightly longer than 24 hours (CDC Yellow Book). Your natural chronotype may play a role too, though that is less well established.
How long does jet lag typically last?
As a rough rule, the CDC puts the average rate of adaptation at about 1 hour per day after eastward travel and 1.5 hours per day after westward travel, so expect roughly a day per time zone going east and somewhat less going west. Shifting your schedule before you fly, using light strategically, and avoiding long naps on arrival may help you adjust faster.
Does napping on arrival day help with jet lag?
A long nap can actually undo the adjustment you’re trying to make. If you need rest after landing, keep it short, about 20-30 minutes, and get outside for natural daylight instead if you’re exhausted.
When should I take melatonin to help with jet lag?
Low-dose melatonin (the CDC says 0.5-1 mg is often sufficient) may work best when timed relative to your destination’s evening, not just taken before any bedtime. Timing matters more than dose here, so it’s worth checking your destination’s schedule before you take it.
When to See a Doctor
Jet lag usually settles by itself, but talk to a doctor or pharmacist before using melatonin or any sleep or wake-promoting medication if you take other medicines, are pregnant, or have a health condition. The CDC Yellow Book cautions against some medication choices for jet lag, so do not improvise with over-the-counter sleep aids. See a clinician if sleep problems, severe daytime sleepiness or low mood continue well after you have adjusted to the new time zone, or if you travel across time zones often and it is affecting your health or work.
Key Takeaways
- Jet lag is your internal clock lagging behind your new local time zone
- Light exposure, timed correctly for your direction of travel, is the main adjustment tool
- Shifting your schedule before you fly and avoiding long naps on arrival speed up recovery
- Expect roughly a day per time zone going east and somewhat less going west; these steps may speed it up
About This Article
Clock changes cause a milder version of the same circadian disruption as jet lag. For tips specific to the twice-yearly time shift, see daylight saving time and sleep.
Written by the Sleep Fixes editorial team. We’re not medical professionals. We research each topic against primary sources and hold ourselves to being critical and thorough about what actually makes it onto the site.
This article is part of Sleep Fixes, a site focused on practical, easy-to-follow solutions for common sleep problems like night waking, dry mouth, overheating, and disrupted sleep.
The content is based on widely accepted sleep principles and common real-world patterns, with a focus on simple changes that may improve sleep quality.
It is not medical advice. If your symptoms are severe, persistent, or worsening, consider consulting a qualified healthcare professional.