Air travel is the cause of jet lag when flights are long and cross several time zones.
It occurs when the body has to adapt to a new day-night cycle after crossing several time zones. Jet lag is mainly due to a disruption in the production rhythm of hormones such as cortisol and melatonin.
As a consequence, the body clock gets thrown off balance, and people feel sleepy when they should be awake, and awake when it is time to sleep.
It is a problem when you travel for business or if you are a flight attendant.
It's also not a good thing when you have just a few days vacation abroad.
The usual recommendation to tackle jet lag is three packets for one flight:
• One packet 1 hour before the flight
• One packet during the flight
• One packet within 1 to 2 hours upon arrival