Jetlag occurs when your body’s internal clock (controlled by a small region of the hypothalamus in your brain) is out of sync with the day-night cycle at your destination. While the internal clock maintains a steady rhythm, it can be gradually adjusted by external cues - primarily light. When you travel across time zones, your local environment shifts immediately, but your internal clock remains aligned with your original schedule and only adjust slowly.
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Your circadian rhythm can be shifted by external cues, known as zeitgebers. JetShift leverages these cues - most notably light exposure and melatonin timing - to realign your internal clock with local time. By applying scientifically validated strategies, JetShift minimizes symptoms like fatigue, poor concentration, and mood disturbances that usually can occur for days or weeks after travelling.
Light is the most potent zeitgeber. The timing of light exposure is critical: It is a common misconception that simply being in natural sunlight is sufficient. It must be synchronized with your current internal clock rather than simply following local daylight hours. Mis-timed light exposure can delay your adjustment, worsening jetlag symptoms. JetShift is designed to help you simulate your personal circadian rhythm and time your light exposure effectively.
Melatonin is a hormone naturally produced by the body, with its synthesis influenced by exposure to light. As a chronobiotic agent, melatonin can adjust your internal clock. Scientific reviews have demonstrated that, when taken at the correct times, melatonin can reduce jetlag symptoms. It is one of the few supplements with proven efficacy in this regard, while many others don't have any relevant evidence while still being advertised with such.
While caffeine has some capacity to affect your internal clock, its effect is much weaker compared to light or melatonin. However, controlled, low-dose caffeine intake can enhance alertness during jetlag. JetShift also provides guidance on optimal caffeine consumption times to avoid interference with sleep quality.
Attempting to sleep based solely on local time, or trying to force sleep during a flight, can worsen jetlag if it is not aligned with your current circadian phase. JetShift takes into account your individual blockers for sleep time and automatically adjusts recommended sleep times. This personalized approach ensures that your sleep is optimized in incremental steps, leading to a smoother transition to the new time zone.
Jetlag is the misalignment between your internal clock and the local day–night cycle after crossing time zones. By utilizing well-timed external cues, such as light exposure, melatonin intake, and controlled caffeine use, you can significantly accelerate the adjustment of your internal clock. JetShift is designed to optimize these cues, helping you reduce the duration and severity of jetlag on your next journey. Find some of the evidence JetShift is based on below.
Melatonin for Jet Lag Management (Cochrane Review)
Herxheimer, A. & Petrie, K.J. (2001). Melatonin for preventing and treating jet lag.
DOI: 10.1002/14651858.CD001520
Melatonin Phase Response Curve
Burgess, H.J., Revell, V.L. & Eastman, C.I. (2008). A three pulse phase response curve to three milligrams of melatonin in humans.
DOI: 10.1113/jphysiol.2007.143180
Light Exposure based on Temperature Minimum
Roach, G.D. & Sargent, C. (2019). Interventions to minimize jet lag after westward and eastward flight.
DOI: 10.3389/fphys.2019.00927
Sleep Schedule Based Shifting
Advancing Circadian Rhythms Before Eastward Flight: A Strategy to Prevent or Reduce Jet Lag
Eastman, C.I., Gazda, C.J., Burgess, H.J., Crowley, S.J., & Fogg, L.F. (2005). Sleep, 28(1), 33–44.
DOI: 10.1093/sleep/28.1.33
Caffeine’s Effect on Circadian Timing
Burke, T.M. et al. (2015). Effects of caffeine on the human circadian clock in vivo and in vitro.
DOI: 10.1126/scitranslmed.aac5125
Caffeine Impact on Subsequent Sleep
Systematic Review & Meta-analysis on caffeine and sleep parameters
DOI: 10.1016/S1087079223000205
