I grew up flying the globe, and now help my patients with their jetlag.
Siberian Ginseng 7.5mls morning and evening, for 3 days before you go, and 3-7 days after arrival. The same on the way back. If you're only there for a short spell, take it continously while youre away and until you're feeling normal again once you're home - you can count a day per hour of time change for your body to adjust, but it will be much less noticeable with the Ginseng. If you're on any medication, check with a Herbalist for interactions before you take anything at all.
Also during the flight, no alcohol and plenty of water. Once you get to your destination, try and adjust to the local time zone as soon as you can - ie try and stay awake as long as you can, and get up in the morning. expose your body to sunlight as that will help readjust your circadian rhythm.
I'm sure this will help. Get in touch if I can be of any more assistance.
Sara Southgate, BSc., ND, Dip Herb, Naturopath and Herbalisthttp://www.sarasouthgate.com