Because of its relationship to your sleeping and waking cycle, you may have heard about taking oral melatonin to help treat jet lag. But does it actually work?

Melatonin is a hormone that’s produced by a small gland in your brain called the pineal gland. It’s secreted in the absence of light, such as during nighttime hours. The presence of light suppresses melatonin production. Because of this, melatonin is involved with our circadian rhythms, which includes our natural sleeping and waking cycle.

Jet lag is a temporary condition that occurs when you move through multiple time zones quickly, such as during a cross-country or overseas flight. This rapid transition disrupts your circadian rhythms, leading to symptoms such as:

  • daytime sleepiness
  • difficulty sleeping at night
  • problems with concentration and focusing
  • disrupted mood

While jet lag is a temporary condition that will ease as you adjust to your new time zone, it can be disruptive during and after a trip. Read on to learn more about the connection between melatonin and jet lag.

Melatonin has been extensively studied as a treatment for jet lag as well as some sleep disorders, such as insomnia. Much of the research regarding melatonin and jet lag has been positive.

A reviewed 10 studies of melatonin as a treatment for jet lag. In 9 out of 10 of the studies the researchers reviewed, melatonin was found to decrease jet lag in people crossing five or more time zones. In the studies, this decrease in jet lag was seen when melatonin was taken close to the local bedtime at the destination.

A more recent reviewed studies of the use of melatonin in various scenarios, including preventing jet lag. This review of eight randomized clinical trials totaling more than 900 participants found that six of the eight trials favored melatonin over the control for counteracting the effects of jet lag.

Melatonin is generally safe for short-term use, although you should still speak to your doctor before using it.

In the United States, melatonin is considered a dietary supplement and the U.S. Food and Drug Administration (FDA) doesn’t regulate its production and use. Because of this, the dosage per capsule may vary by brand and the presence of possible contaminants cannot be ruled out.

You should avoid taking melatonin if you:

Melatonin also has some possible drug interactions. Consult your doctor before using melatonin if you’re taking any of the following:

You should also avoid taking melatonin with alcohol.

Are there side effects?

When taking melatonin, you may experience the following side effects:

  • headache
  • nausea
  • sleepiness
  • dizziness

Rarely, melatonin can cause changes in mood, depression, anxiety, or very low blood pressure. Stop taking melatonin and call your doctor if you experience any of these serious side effects.

Because melatonin causes drowsiness, you shouldn’t drive or operate machinery within five hours of taking the supplement.

Guidelines on the proper dosage and timing for melatonin vary. Speak with your doctor for their recommendations before using it.

Generally, if you choose to use melatonin for jet lag, you take it after you arrive at your destination. However, some does suggest taking it on the day of travel at your ideal bedtime in your destination time zone, particularly if you’ll be crossing five or more time zones.

Effective dosages can range from just 0.5 milligrams to five milligrams or higher.

While traveling, particularly if you’re traveling to a time zone where the local time is ahead of your time, plan to take melatonin at the local time before you plan to go to bed.

If you’re traveling westward and trying to adapt to an earlier time, it may be beneficial to consider taking melatonin in the morning. This is because melatonin can delay the waking portion of your circadian rhythms.

You can take melatonin between 30 minutes to two hours before you plan to sleep.

Since light naturally suppresses melatonin levels in your body, also plan to dim or darken the lights in your room, and avoid using devices such as your smartphone or laptop.

Prior to your travels, it may be helpful to do a trial run with melatonin at home. That way, you’ll be aware of how your body reacts to it before you leave home. This can also help you to figure out the optimal timing and dosage for you personally.

When to take melatonin

  • When crossing fewer than five time zones, take melatonin after you arrive at your destination.
  • When crossing five or more time zones, take melatonin on the day of your travel.
  • When traveling to a time zone where local time is ahead of your time, take melatonin at your expected bedtime in the new time zone.
  • Take melatonin 30 minutes to 2 hours before you plan to go to sleep.

There are some other things that you can do to help prevent jet lag, including:

Before you depart

  • If you’re traveling for an important event, consider arriving a day or two earlier so that you can properly adjust to your new time zone.
  • Gradually adapt to your new schedule before your departure by going to bed an hour earlier or later than normal each evening, depending on the direction you’re traveling.
  • Be sure that you’re well rested before your travels. Being sleep-deprived to begin with can exacerbate jet lag.

On your flight

  • Stay hydrated. Dehydration can make the symptoms of jet lag worse.
  • If you would normally be sleeping at the time of your flight, such as on a flight from the United States to Europe, try to get some sleep. Using an eye mask, earplugs, or both may be helpful.
  • Limit your caffeine and alcohol consumption. Not only can both increase your need to urinate, which can disrupt your sleep, but they can also make the symptoms of jet lag feel worse.
  • Consider asking your doctor for a prescription sleeping pill such as zolpidem (Ambien) or eszopiclone (Lunesta) to take during your flight to help with the duration and quality of your sleep. It’s important to note that while these medications will help you sleep on the flight, they won’t treat the circadian rhythm disturbances caused by traveling.

After you arrive

  • Stay on your new time schedule. Try to go to bed at a time that would be normal for that time zone, regardless of how tired you may feel. Consider setting an alarm in the morning so that you don’t sleep too late.
  • Go out and about during the day. Natural light is one of the most important parts of resetting your sleeping and waking cycle. Exposing yourself to morning light can help you adapt when traveling eastward while exposing yourself to evening light can help when traveling westward.

Taking oral melatonin before or during your travels may help to relieve the symptoms of jet lag. Because there are varied guidelines on how to use melatonin for jet lag, you should be sure to get your doctor’s recommendations before using it.