It's always been a mystery how jet lag affects some travellers and not others, but no more - the culprit is a hormone called vasopressin. Vasopressin is responsible for maintaining our internal clocks, and sensitive people can be more susceptible to its effects.

Researchers genetically engineered mice that do not respond to vasopressin. Both engineered and normal rodents lived in a set cycle of light and dark for 2 weeks. Then the researchers changed the light cycle by eight hours. And the vasopressin-insensitive mice recovered from their induced jet lag much more quickly than did their hormone-sensitive peers. 

For many people, jet lag isn't simply an inconvenience. The symptoms can be extreme, causing your vacation to be wasted as you spend time catching up on sleep. While there's no cure for jet lag yet, the article Cutting Hormone Could Trip Jet Lag offers us a little hope that a remedy is on the way.