Christopher Lotz, an attorney from San Antonio, Texas, has his travel routine down to a science. Three days before a transatlantic flight, he begins going to bed and waking up earlier, nudging his body clock toward European time. Then, on the day of his flight, he eats his last meal at 2 p.m. (dinnertime in Europe) and heads to the airport for a late-evening departure. Once onboard the plane, he pops a dose of the prescription sleeping pill Ambien, dons eyeshades and earplugs and settles into his cramped coach seat. "Before you know it I'm asleep, and I wake up when they're doing the morning meal service," he says. Coming off the plane, he feels refreshed and ready to tackle client meetings--without needing a nap first.

Jet lag has been the bane of business travelers since the birth of international flight. But while aviation technology has advanced well beyond Charles Lindbergh's monoplane, a cure for "circadian-rhythm stress" has remained as elusive as a fix for the common cold. Type the words "jet lag" and "remedy" into a search engine, and you'll find everything from fad diets to homeopathic pills to portable "light therapy" lamps. (Some fliers, no doubt, have tried them all.) A traveler's best bet, experts say, is to follow Lotz's approach: get plenty of rest during your flight and, when possible, sync your sleep schedule with that of your destination a few days ahead of time.

Of course, not everyone can sleep on a noisy jet. That's why more travelers are experimenting with prescriptions, often (and unwisely) trading tips and tablets at airports. Justin Shasha, a 29-year-old management consultant from London, recalls watching a group of well-dressed middle-aged women--or "yummy mummies" in British terminology--swapping meds at a first-class lounge in Honolulu. "It was like a street corner in the 'hood," he says. When Shasha approached, an Australian woman handed him some "excellent pink pills" that turned out to be the anti-anxiety drug propranolol. He says they helped him sleep like a baby all the way to Sydney.

In fact, travelers should be extremely cautious with pills. Dr. James Walsh, chairman of the National Sleep Foundation in Washington, D.C., says he'd recommend only two medications to help fliers sleep: the prescription drugs Ambien and Sonata (consult your doctor before taking any drugs). "You want a medication that stays in your body four to six hours," he says. Anything longer lasting--antihistamines, antidepressants, anti-anxiety pills and over-the-counter sleep aids--can make you woozy. (Sonata promotes sleep for about four hours, Ambien for about six hours.) To sleep more soundly, Walsh also recommends taking the pills for the first two nights of a trip. "If you can eliminate sleep deprivation," he says, "that's half of it."

Though Ambien is becoming more popular with travelers, melatonin still seems to be the No. 1 remedy. The hormone, which stirred a craze when it was first released as a supplement in the mid-1990s, is secreted by the brain at night to signal the time for sleep. A poll of 5,000 travelers conducted last summer by the group Leading Hotels of the World found that 21 percent of those who used any jet-lag remedy relied on melatonin, compared with 10 percent for Ambien and 10 percent for over-the-counter sleep aids.

But despite travelers' enthusiastic reviews, there's little scientific evidence that melatonin works as a sleep aid. Most recent studies that have compared the hormone with a placebo have shown no sleep benefit with the supplement, reports the National Sleep Foundation ( Researchers, however, have found it to be effective in advancing people's internal clocks before an eastward flight. Charmane Eastman, a circadian-rhythms scientist at Chicago's Rush University Medical Center, recently published a study in which she used melatonin and exposure to artificial light in the morning to switch volunteers to an earlier sleep schedule over the course of three days. (Subjects went to sleep one hour earlier each night and woke up an hour earlier each morning.) Melatonin, administered at a low dose--.5mg--five hours before bedtime, says Eastman, helped her volunteers fall asleep earlier. Typically it takes one's body 24 hours to adjust to each new time zone--meaning that an L.A. resident flying to London might take eight days to feel in sync. As people age, the adjustment becomes more difficult. Eastman's changes would give travelers a leg up in adapting to a time zone five to seven hours ahead. While some might be skeptical about altering their habits so dramatically, Eastman says she's persuaded even her busiest friends to follow the regimen.

Sound like more retraining than you're willing to do? Travelers can always follow Israel Baron's relaxed approach to flying (if they can afford it). The Los Angeles-based film producer flies twice a month to London on Virgin Atlantic and insists jet lag is a state of mind. His way of fighting fatigue? He flies first class, sleeps on a flat bed and never misses an in-flight massage. "The main thing is to feel comfortable," he says. For him, beating jet lag is a matter of beating stress. For most travelers, that's easier said than done. Pass the Ambien.