How to Beat Jet Lag: A Traveler's Guide to Resetting Your Body Clock

Crossing several time zones can leave your mood, focus, and sleep out of step for days. This guide explains what jet lag is, how to prepare before you fly, and which habits during the trip help your body clock settle in faster.

Few travel moments are less glamorous than staring at a hotel ceiling at 3 a.m. in a brand-new city, wide awake. Jet lag is common, but it doesn't have to take over your trip. A few strategic adjustments before and during your journey can significantly shorten recovery time.

What Jet Lag Really Is

Jet lag is a temporary sleep problem that happens when your body's usual daily rhythms don't match a new time zone. It most often strikes after crossing more than three zones, though anyone who travels far can feel it. Mood, concentration, and physical and mental performance can all take a hit.

Shift Your Schedule First

The easiest fix starts at home. In the days before you fly, nudge your sleep toward your destination's clock. Heading west, go to bed an hour or two later than usual. Heading east, go to bed an hour or two earlier.

Even a shift in the final one to two days helps. Whenever possible, arrive at least two days before an important event, and eat lighter meals leading up to the flight, since gastrointestinal upset is a frequent symptom.

Let Light Do the Work

Light has the strongest pull on your body clock, and sunshine counts even on a cloudy day. Once you land, spend daytime hours in natural light to speed up the adjustment.

Artificial light also plays a role — including screens from phones and laptops — so avoid exposure during scheduled dark hours. If natural light isn't available, bright indoor lights, devices, or a light therapy lamp can stand in.

Timing cuts the other way as well. Light at the wrong moment can push your clock in the wrong direction, so dim the lamps, skip screens, or wear sunglasses when needed. That doesn't call for total darkness, only less light than usual.

Think Carefully About Melatonin

Your body makes melatonin, the hormone that signals darkness, starting two to three hours before your usual bedtime. Studies suggest that low-dose supplements of one to three milligrams may help realign your clock when taken at the right time.

Since melatonin can shift the clock earlier or later, timing is everything. In the U.S., it is sold over the counter, but in most countries, it requires a prescription.

Some people experience grogginess or stomach problems, and it can interact with other medications, so check with your doctor first and never try it for the first time on the plane.

Habits for the Journey

If your destination is more than three hours from home, follow its sleep and wake schedule as soon as you arrive. Keep meals small, skip alcohol because it disrupts sleep, and drink plenty of water.

Use caffeine and exercise to stay alert during the day, but not in the evening. If you need a nap, keep it to 15 or 20 minutes. If jet lag hits you hard, ask your doctor about sleep aids.

Combining these steps works better than relying on any one of them. And if you tend to feel unwell once vacation starts, find out why you always get sick on vacation, and what experts explain about the let-down effect.