Why east is worse
Your internal clock runs slightly longer than twenty-four hours left to itself, so stretching a day is easier than shortening one. Flying west lengthens the day and the body adapts reasonably well. Flying east shortens it and the body resists.
As a rough guide you recover about one time zone a day, faster westbound and slower eastbound. London to New York is tolerable; London to Tokyo takes most of a week. That arithmetic is worth doing before you book a meeting for the morning after a long eastbound flight.
Light is the lever
Daylight resets the body clock more powerfully than anything else, and it works in both directions - well-timed light helps, badly timed light makes jet lag worse. Travelling east, morning light at your destination pulls your clock forward. Travelling west, late afternoon and evening light pushes it back.
This is why standing outside for twenty minutes at the right time beats most of what you can buy. We will work out which end of the day you want light at for your particular direction and distance, because getting it backwards actively prolongs the problem.
- Set your watch to the destination when you board, and eat and sleep by it
- Travelling east: seek morning light, avoid bright evening light
- Travelling west: seek late afternoon light, avoid early morning light
- Keep alcohol down on the flight - it fragments the sleep it seems to help
- Short naps of twenty to thirty minutes only, and not late in the day
- For a trip of two days or less, consider staying on UK time rather than adapting twice
Medicines, and what they are for
Melatonin is the body's own signal that it is night, and taken at the right time it shifts the clock rather than simply sedating. The timing is the whole of it - taken at the wrong hour it can move your clock the wrong way. Our price list shows what a pack of thirty costs.
It is not for everyone and it needs a pharmacist consultation: it interacts with some medicines, including anticoagulants and some anti-epileptics, and it is not suitable in pregnancy or while breastfeeding.
Sleeping tablets are a different thing. They can get you through a night but do nothing to move the clock, so the underlying problem is still there in the morning. We would rather talk about light and timing first, and use a tablet where it genuinely helps.
Long flights carry other things worth planning for
Sitting still for eight hours raises the risk of a clot in the leg. Moving around the cabin, flexing your ankles while seated, and drinking water rather than relying on tea and alcohol all help. Compression stockings are worth discussing if you have had a clot before, have had recent surgery, are pregnant, or are flying very long haul.
If you take medication at fixed times, a long flight across several zones needs a plan - particularly insulin, anticoagulants, hormonal contraception and anything taken twice daily. Bring your repeat list to the appointment and we will write out the timings for the journey.