“Jet lag is much milder on a private jet.”
Verdict: Manufacturers make a real case: newer jets pressurise the cabin to a lower 'altitude' (as low as 2,800–4,800 ft versus 6,000–8,000 ft on most airliners), pump in 100% fresh air, keep humidity higher and let you lie flat. Those things demonstrably reduce fatigue and dehydration. Whether they reduce *jet lag* — which is a circadian-rhythm problem caused by crossing time zones — is much less certain.
Gulfstream, Bombardier and Dassault have competed for years on cabin altitude. A G700 at 41,000 ft keeps its cabin at roughly 2,900 ft; a Global 7500 at 45,000 ft sits at about 4,850 ft; typical airliners are pressurised to 6,000–8,000 ft, though the Boeing 787 and Airbus A350 also manage around 6,000 ft. Lower cabin altitude means more oxygen in the blood, and studies of long-haul crews and passengers link higher cabin altitudes to headaches, poorer sleep and greater fatigue.
Add genuinely fresh (not recirculated) air, humidity that can be several percentage points higher, a flat bed and the ability to depart at an hour that suits your body clock, and it is plausible that you arrive feeling considerably better than after a night in economy.
But jet lag is your body's clock disagreeing with the local sun, and no cabin fixes that. Crossing eight time zones takes your circadian system several days to reset regardless of how you flew. The honest framing: private jets reduce travel fatigue substantially, and that can make jet lag feel milder. Whether it is milder has not been established by independent research.
Sources: gulfstream.com · en.wikipedia.org
