(Epistemic status: not particularly supported by science, works on my machine, your results may vary.)
I’ve been traveling across an 8-hour timezone boundary (for work). I rarely experience much jet lag anymore (if my flight lands in the morning, I can still get a productive day; if my flight lands at night I’ll fall asleep properly that night). So I wanted to share how I’ve achieved this and how you (maybe) can too.
Short version – use melatonin supplements and light tricks to force-adjust your sleep cycle, and withdraw from caffeine to make yourself sleepy.
Piotr Wozniak (otherwise known as “the SuperMemo guy”) and a few other people on the internet have a model of sleep which is based on a two-component model: a circadian (daily cycle) component and a homeostatic (building-up-pressure) component. Here’s where he describes it: http://www.supermemo.com/articles/sleep.htm - search for circadian.
The circadian component is regulated by the natural hormone melatonin. Your brain produces melatonin on an internal “clock” when it thinks it is about to get dark out. This process seems to be mostly based on the clock, but the clock will slowly adjust based on feedback from blue/white light during the daytime. A big part of jet lag is that your circadian clock is totally wrong for the new time zone and so you aren’t sleepy when you should be, or you get sleepy during the day.
(Note – the well-known tool Flux (https://justgetflux.com/) works based on reducing blue light emitted by screens at night, allowing the brain to produce melatonin.)
But! We can take melatonin supplements. My theory (which has some shaky scientific basis, google it) is that supplementing melatonin “resets” the circadian clock much faster than just looking at blue light.
However, this is not by itself sufficient – when I take melatonin at weird times, I often get an unusual sensation of “not sleepy but still want to close my eyes and not move much” feeling.
So phase two is adjusting the homeostatic component. Without something like an adenosine supplement, this seems harder to adjust at will - but then I reread Wozniak and he was very clear in his warnings about caffeine: caffeine has an inhibitory effect on the neurotransmitter adenosine, which is what’s responsible for the homeostatic sleepiness feeling.
Credit here goes to my colleague Drew, who figured this out first through self-experimentation: stop caffeine before your flight.
The way caffeine tolerance works is that your brain produces more adenosine and more sensitive receptors, to compensate for caffeine’s inhibitory effect. That’s why you get extra tiredness when you withdraw from caffeine. Yes, you will have headaches and be a bit more irritable too, but (in my and Drew’s experience) that’s not a blocker for sleeping on the plane.
OK, so here’s the full set of recommendations:
- Become somewhat tolerant to caffeine in your daily life. I normally drink ~1-2 cups of coffee each day.
- Don’t consume any caffeine for 16-24 hours before your flight.
- Before the flight, compute your normal bedtime hour in the new time zone, and set a timer for then. Take a dose of melatonin supplement at that time, whether it be before you get on the plane, or while you’re actually on the plane.
- Pack a great eye mask, earplugs, a neck pillow, smartphone
- Once you get on the plane: reset all your personal clocks to the destination time zone. From now on, your night and day are the destination’s night and day.
- On long flights they usually have a “night” period and a “day” period. Ignore this. Make your own night and day by putting on your eye mask at night, and watching a movie/playing a game/turning on your seat overhead lighting for day.
- On the flight, try to sleep during the night (and only during the night). Take melatonin ~30 minutes before you want to sleep.
- If you find yourself having trouble sleeping during the night, read for 30 minutes or an hour, and then try again.
- Be awake during the day on the flight.
- Take caffeine on the morning of your first full day of arrival.
- If you are so sleepy that you can’t function, set a timer and take a 20 min nap no more than once every 2 hours. At a minimum, you should try to stay awake during the day until it gets dark out. If you’re super sleepy, going to bed at like 8pm is probably fine; you’ll get extra sleep and probably wake up with the sun next day (but set an alarm for 9am to be sure).
- Don’t forget to take one more melatonin on the night after you land to help adjust.