Jet Lag: What It Does to Your Body and How to Recover

Jet lag occurs when your internal circadian clock is out of sync with the time zone you are in. Travelling across 3 or more time zones typically triggers symptoms. Symptoms include fatigue and drowsiness, insomnia, difficulty concentrating, gastrointestinal issues, and mood changes. Eastward travel tends to cause worse jet lag than westward travel because advancing your clock (going to sleep earlier) is harder than delaying it. Evidence-based strategies to manage jet lag include pre-adjusting your schedule (shift bedtime by 30 minutes per day for several days before departure), strategic light exposure (seek morning light at your destination to advance your clock, or evening light to delay it), short-term melatonin use (0.5 to 5 mg taken at bedtime at your destination; timing matters more than dose), staying hydrated and limiting alcohol and caffeine on the flight, and taking short naps (under 30 minutes) if needed to avoid worsening nighttime sleep. Most people adjust within 1 to 2 days per time zone crossed. If jet lag significantly affects your functioning or you travel frequently, discuss options with your physician. *This article is for informational purposes only.*

This article is for informational purposes only and does not constitute medical advice. Content reviewed by licensed Canadian physicians. Last updated February 2026.