• Resets your body clock naturally after long flights
  • Available in 2mg (off-label for jet lag) and 3mg strengths 
  • Non-addictive and clinically proven for sleep adjustment

How it works?

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Overview

Jet lag happens when your internal body clock (circadian rhythm) is out of sync with local time after crossing multiple time zones. While symptoms usually pass, they can be disruptive — especially if you’re travelling for work, an event, or a holiday.

What is Melatonin

Melatonin is a naturally occurring sleep hormone. By supplementing melatonin at the right time, it helps reset your sleep–wake cycle, making it easier to drift off at night and feel more awake during the day.

  • Circadin 2mg (modified-release): Licensed in the UK for insomnia in over-55s, but commonly prescribed off-label for short-term jet lag.
  • Melatonin 3mg: Available in some formulations and used off-label in the UK.


Both strengths work by gently restoring melatonin levels to support a faster adjustment to new time zones.

Directions

  • Take 1 tablet 1–2 hours before your intended bedtime in the new time zone for up to 5 days.
  • Melatonin should be swallowed whole with water — do not crush or chew.
  • Use for a few nights after travel, or as directed by your prescriber.
  • Avoid alcohol, as it reduces effectiveness.

Side Effects

Most people tolerate Melatonin well. Side effects, if they occur, are usually mild and short-lived.

Common (may affect up to 1 in 10 people):

  • Headache
  • Drowsiness or fatigue
  • Nausea


Uncommon (may affect up to 1 in 100 people):

  • Dizziness
  • Irritability or mood changes
  • Abdominal pain


Rare but serious (seek urgent medical help):

  • Severe allergic reaction (rash, swelling, difficulty breathing)


Disclaimer: This is not a complete list of side effects. Always read the patient information leaflet that comes with your medicine for full details. If you notice anything unusual or concerning, stop taking Circadin and seek medical advice promptly. In an emergency, call 999 or go to A&E.

Warnings

  • For short-term use only unless otherwise directed.
  • Avoid driving or operating machinery if you feel drowsy.
  • Do not use if allergic to melatonin or any ingredients.
  • Speak to your prescriber before use if you are pregnant, breastfeeding, or taking other medicines that affect sleep (such as sedatives or antidepressants).
  • Circadin 2mg is licensed in the UK for insomnia but often used off-label for jet lag.
Frequently asked questions

  • What is Melatonin 2mg and how does it work?

    Melatonin 2mg is a sleep-regulating hormone used to help adjust your body clock, especially after long-distance travel. It supports natural sleep patterns by signalling to the brain that it is time to rest. This can make it easier to fall asleep and reduce the symptoms of jet lag after changing time zones.

  • How should I take Melatonin 2mg for jet lag?

    Melatonin 2mg is best taken at your destination’s local bedtime for a few nights after arrival. This helps your body reset to the new time zone more quickly. Swallow the tablet whole and avoid taking it too early in the evening, as incorrect timing may worsen sleep disruption.

  • How long does Melatonin 2mg take to work?

    Melatonin 2mg usually begins working within one to two hours, helping your body prepare for sleep. Its prolonged-release design supports a more natural pattern of overnight sleep. Effects vary between individuals, but most travellers notice improvements within the first couple of nights.

  • Is Melatonin 2mg safe to use short term?

    Yes. Melatonin 2mg is considered safe for short-term use in adults when taken as directed. Most people tolerate it well, though mild side effects such as headache or next-day drowsiness may occur. Avoid use during pregnancy, breastfeeding or with interacting medicines unless advised by a clinician.

  • Can Melatonin 2mg help reduce jet lag symptoms?

    Yes. Melatonin 2mg is one of the most effective methods for reducing jet lag symptoms because it helps shift your internal body clock. Many travellers find they fall asleep easier, wake less overnight and adjust faster to the new time zone when melatonin is used correctly.

  • Can I take Melatonin 2mg before my flight?

    Some travellers take melatonin before or during an eastbound flight to begin adjusting their sleep schedule. This can be helpful when the flight overlaps with the destination’s night-time. However, avoid taking melatonin if you need to remain alert during the journey.

  • Can I drink alcohol while taking Melatonin 2mg?

    Alcohol may reduce melatonin’s effectiveness and increase drowsiness or impaired coordination. If you choose to drink, keep consumption light and avoid alcohol close to bedtime. Using melatonin alongside heavy drinking is not recommended as it can disrupt sleep quality.

  • What are the side effects of Melatonin 2mg?

    Some people may experience mild side effects including headache, dizziness, stomach upset or next-day sleepiness. These effects are usually temporary and settle once your sleep pattern adjusts. If symptoms persist or become troublesome, speak to a clinician before continuing.

  • Who should not take Melatonin 2mg?

    Melatonin 2mg is not suitable if you are pregnant or breastfeeding, have autoimmune conditions or take certain medicines such as anticoagulants, immunosuppressants or sedatives. Always check with a clinician if you have long-term health issues or take regular medication.

  • Can I drive after taking Melatonin 2mg?

    Driving should be avoided for several hours after taking melatonin as it can cause sleepiness and slower reaction times. Use melatonin only when you can sleep afterwards and do not operate machinery if you still feel drowsy the following morning.

  • How many nights should I take Melatonin 2mg when travelling?

    Most travellers benefit from taking Melatonin 2mg for two to four nights after arriving in a new time zone. This allows your circadian rhythm to stabilise as your sleep and wake cycle adjusts. A longer course is rarely required unless advised for a specific sleep issue.

  • Does Melatonin 2mg interact with other medications?

    Melatonin may interact with anticoagulants, antidepressants, antiepileptics, blood pressure medicines and sedatives. These interactions can increase drowsiness or alter how the medicines work. If you take long-term medication, speak to a clinician before using melatonin for jet lag.

  • Can Melatonin 2mg help restore sleep after returning home?

    Yes. Many travellers struggle with disrupted sleep even after returning from their trip. Taking Melatonin 2mg at your usual bedtime for a few nights may help reset your sleep pattern and reduce early-morning waking or insomnia caused by residual jet lag.

  • Is prolonged-release melatonin better than immediate-release for jet lag?

    Prolonged-release melatonin (such as the 2mg tablet) supports sustained overnight sleep, while immediate-release helps you fall asleep faster. For many travellers, prolonged-release provides a steadier effect when adjusting to a new schedule. The optimal choice depends on your sleep pattern and travel direction.

  • Can Melatonin 2mg be used long term?

    Melatonin 2mg is licensed for short-term use and not intended as a long-term sleep aid unless recommended by a clinician. If persistent sleep problems continue after travel, further assessment may be required to identify underlying causes and ensure melatonin remains appropriate.