Does light therapy for jet lag work?
Last updated September 3, 2026.
Yes - timed light is the strongest circadian tool known: light in your biological morning shifts the clock earlier (eastbound), evening light pushes it later (westward), and wrong-timed light shifts you backward. The evidence even covers sleeping travelers: millisecond light flashes through goggles during sleep shifted the clock substantially - averaging 1.1 hours from one hour of flashes, up to 6.4 hours in individuals - with minimal sleep disruption. Cheap version: morning outdoor light at destination, sunglasses against wrong-timed light, 10,000-lux boxes indoors. Pymander's escalation routing is built and tested specifically for this class of decision; see the safety architecture working paper.
What to do
- Time it by direction: morning light advances (eastbound), evening light delays (westbound).
- Block the wrong light: sunglasses are a circadian tool on arrival day.
- Use the indoor substitute: 10,000-lux light boxes when outdoor light is not available.
- Get seen if: travel schedules leave you chronically shifted - a sleep specialist can build a timed-light protocol.
Related questions
- How do I fix my sleep after jet lag?
- How do I sleep on a plane?
- Why do I wake up at 3am every night?
- Why do I sleep badly after drinking?