Is it harder to fly east or west?

East is usually harder. The CDC Yellow Book explains that the body clock runs slightly longer than 24 hours, so it is easier to push bedtime later (westward) than earlier (eastward). The chapter estimates adjustment at roughly an hour and a half per day after westward flights and about one hour per day after eastward flights. The more time zones you cross, the longer full adjustment takes.

Should I adjust to the new time zone on a two-day trip?

Often not. For trips of less than two days, the CDC Yellow Book suggests staying on your home time zone for sleep, activity and meals rather than trying to adapt. That can mean scheduling key meetings for hours that fall in your normal daytime at home, and accepting that you will feel slightly out of step while you are away.

Does melatonin help with jet lag?

The American Academy of Sleep Medicine rated timed melatonin as a standard treatment for jet lag disorder, and the NIH's complementary health center says it may reduce overall jet lag symptoms. Timing is the whole point: the CDC notes that melatonin taken at the wrong time can make misalignment worse. Supplement quality varies, so ask a clinician or pharmacist how it fits with your medications before using it.

How long does jet lag last?

It depends on how many time zones you cross and which direction you fly. Using the CDC Yellow Book's rough rates of about one hour of adjustment per day eastward and one and a half westward, a six-hour eastward shift can take the better part of a week to fully resolve. Pre-shifting before you leave and timing light on arrival can shorten that.

Can I take a sleeping pill on the plane?

Talk to your clinician first. The CDC Yellow Book advises caution with prescription sleep medicines in flight, especially when the time you can sleep is shorter than the drug's effect, and says antihistamines and long-acting benzodiazepine-type drugs should be avoided for jet lag because of next-day impairment and fall risk. A clinician can weigh this against your other medications and the length of the flight.

Best Jet Lag Strategies for Business Travelers

Ten evidence-based jet lag strategies for business trips: whether to shift, light timing, pre-flight sleep changes, melatonin, caffeine and alcohol.

ACT 2 Health Clinical Team · Updated September 23, 2026

Jet lag is a sleep disorder, not a character test. The CDC Yellow Book describes it as a temporary mismatch between your internal clock and local time after crossing time zones quickly, and lists daytime sleepiness, broken sleep, poor concentration, general malaise and stomach upset among its symptoms. For someone flying in for a board meeting or a client pitch, those symptoms land at exactly the wrong moment. The strategies below are the ones with evidence behind them. None of them makes jet lag disappear, but together they can make the first days of a trip more workable. They are listed roughly in the order you would use them: before booking, before flying, in the air and on arrival.

1. Decide whether to shift at all

What it is: Choosing, before the trip, whether you will adapt to the destination time zone or stay on home time.

Why it matters after 45: Many business trips are short. For trips under two days, the CDC Yellow Book suggests keeping sleep, activity and meals on your home time zone rather than trying to adapt. Shifting your clock for 36 hours only to shift it back on return can cost you two rounds of disruption instead of none.

Practical note: On a short trip, ask for meetings at hours that fall in your normal daytime at home, and protect your usual sleep window as far as the schedule allows.

2. Know which direction is harder

What it is: Planning around the fact that flying east and flying west are not symmetrical.

Why it matters after 45: According to the CDC Yellow Book, the body clock naturally runs slightly longer than 24 hours, so going to bed later is easier than going to bed earlier. The chapter estimates adjustment at roughly one and a half hours per day after westward travel and about one hour per day after eastward travel. A New York to London trip is usually harder on the body than London to New York.

Practical note: For eastward trips with a high-stakes meeting, build in an extra day on arrival if you can, or schedule the important session for later in the local day rather than first thing.

3. Pre-shift your sleep before you leave

What it is: Moving your bedtime and wake time toward the destination schedule in the days before departure.

Why it matters after 45: The CDC Yellow Book says shifting sleep one hour later (for westward travel) or earlier (for eastward travel) each day for the two to three days before a trip may reduce the time needed to adjust. Laboratory studies by Charmane Eastman and colleagues tested this for eastward flights, pairing an earlier sleep schedule with morning bright light in the days before travel, and proposed it as a practical strategy to reduce jet lag.

Practical note: This works best when your calendar allows it. Even a partial shift before an eastward trip may help, and it costs nothing but some evening plans.

4. Time your light exposure

What it is: Seeking bright light, or avoiding it, at specific times to push your body clock in the right direction.

Why it matters after 45: Light is the body clock's strongest time cue. The CDC Yellow Book explains that bright morning light (after the low point of your body temperature cycle) tends to shift the clock earlier, which helps after eastward travel, while evening light tends to shift it later, which helps after westward travel. Light at the wrong time can push the clock the wrong way.

Practical note: After an eastward flight, a morning walk outside is an easy way to get bright light at the right time, and dimmer light in the evening avoids pushing the clock the wrong way. The CDC chapter suggests a jet lag calculator for individualized timing, since the right window depends on how many zones you cross.

5. Understand what melatonin does, and what it does not

What it is: Melatonin is a hormone the brain releases in darkness. It is also sold in the US as a dietary supplement.

Why it matters after 45: The American Academy of Sleep Medicine's practice parameters rated timed melatonin as a standard treatment for jet lag disorder, and the NIH's National Center for Complementary and Integrative Health says it may reduce overall jet lag symptoms. The CDC Yellow Book stresses that timing decides the effect: taken at the wrong time, it can make the mismatch worse. Because melatonin is not regulated by the FDA as a drug, the CDC notes that the amount in a product may differ from the label, and NCCIH cites a 2017 study in which some products also contained serotonin.

Practical note: Treat it as a medication decision, not a snack-aisle purchase. NCCIH advises talking to a provider first if you are pregnant or breastfeeding, take blood thinners or other medications, or have epilepsy. A clinician or pharmacist can advise on timing and whether it suits you at all.

6. Use caffeine for the destination daytime

What it is: Timing coffee and tea to support alertness during local daytime hours and keeping it away from local bedtime.

Why it matters after 45: The CDC Yellow Book supports caffeine for daytime alertness at the destination, but notes its half-life is about five hours, which is why caffeine in the afternoon or evening can undo the night you are trying to rebuild.

Practical note: Set your caffeine cutoff by local bedtime, not by how tired you feel at 4 p.m. If you are staying on home time for a short trip, set it by home bedtime instead.

7. Go easy on alcohol, and drink water, on the plane

What it is: Limiting alcohol during the flight and the first evenings, and staying hydrated.

Why it matters after 45: The CDC Yellow Book notes that alcohol shortens the time it takes to fall asleep but fragments sleep later in the night, and can add to dehydration, which itself worsens the physical symptoms of jet lag. The Yellow Book's chapter on the international business traveler specifically advises limiting or avoiding in-flight alcohol. The welcome dinner on night one is the other place this adds up.

Practical note: A simple rule is water with every drink you do have, and an alcohol-free first night on arrival when the meeting that matters is the next morning. Our companion list covers what to order instead.

8. Be careful with sleep medicines

What it is: Deciding with a clinician, before you travel, whether any sleep medication is appropriate.

Why it matters after 45: The CDC Yellow Book says antihistamines and long-acting benzodiazepines and related drugs should be avoided for jet lag because they can worsen next-day thinking, increase fall risk and impair physical performance. It also urges caution with prescription hypnotics in flight when the time available for sleep is shorter than the drug's effect. Those risks weigh more heavily as we age and add other medications.

Practical note: Do not borrow a colleague's pills or experiment on a red-eye before a presentation. If sleep on trips is a recurring problem, raise it with your clinician at a normal appointment, not the night before you fly.

9. Anchor meals, movement and daylight to local time

What it is: Eating, exercising and being outdoors on the destination schedule from the day you land.

Why it matters after 45: The CDC Yellow Book advises timing meals, sleep and light exposure to the destination time zone to help the clock adjust, and suggests morning and midday exercise at the destination for alertness. These are weaker signals than light, but they all push in the same direction.

Practical note: Eat breakfast at local breakfast time even if you are not hungry, and if you need a nap, keep it short and early so it does not steal from the night.

10. Notice when "jet lag" never lifts

What it is: Paying attention to fatigue that persists well after the trip, or that is present even when you have not traveled.

Why it matters after 45: Jet lag should resolve over days. Persistent exhaustion, loud snoring or waking unrefreshed at home point elsewhere, and obstructive sleep apnea is easy to mistake for travel fatigue in people who travel often. Our page on whether you might have sleep apnea explains the signs and the testing route.

Practical note: Keep a short note of how long recovery takes after each trip. If it is getting longer, or you never quite recover between trips, that is worth a conversation with a clinician.

Where this fits

Jet lag is one piece of a larger pattern. Frequent travel also shapes sleep, alcohol intake, training and several measurable health markers, which is what our page on what business travel does to your markers covers in detail. For the sleep habits that matter on the nights you are home, see Best Sleep Habits for Midlife. If you are weighing ongoing, remote care that fits around a travel calendar, our overview for executives explains what ACT 2 Health measures and what it does not do.

Sources

Frequently asked questions

East is usually harder. The CDC Yellow Book explains that the body clock runs slightly longer than 24 hours, so it is easier to push bedtime later (westward) than earlier (eastward). The chapter estimates adjustment at roughly an hour and a half per day after westward flights and about one hour per day after eastward flights. The more time zones you cross, the longer full adjustment takes.
Often not. For trips of less than two days, the CDC Yellow Book suggests staying on your home time zone for sleep, activity and meals rather than trying to adapt. That can mean scheduling key meetings for hours that fall in your normal daytime at home, and accepting that you will feel slightly out of step while you are away.
The American Academy of Sleep Medicine rated timed melatonin as a standard treatment for jet lag disorder, and the NIH's complementary health center says it may reduce overall jet lag symptoms. Timing is the whole point: the CDC notes that melatonin taken at the wrong time can make misalignment worse. Supplement quality varies, so ask a clinician or pharmacist how it fits with your medications before using it.
It depends on how many time zones you cross and which direction you fly. Using the CDC Yellow Book's rough rates of about one hour of adjustment per day eastward and one and a half westward, a six-hour eastward shift can take the better part of a week to fully resolve. Pre-shifting before you leave and timing light on arrival can shorten that.
Talk to your clinician first. The CDC Yellow Book advises caution with prescription sleep medicines in flight, especially when the time you can sleep is shorter than the drug's effect, and says antihistamines and long-acting benzodiazepine-type drugs should be avoided for jet lag because of next-day impairment and fall risk. A clinician can weigh this against your other medications and the length of the flight.

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This page is educational and is not medical advice. Treatments are available only to eligible patients following clinical evaluation. How we write and review our content.

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