That there is a significant craving for such control, especially among professional elites in a world increasingly defined by frequent global travel and a nonstop stream of digital information is abundantly evident. Approved in 2002, Provigil has enjoyed phenomenal sales growth: $5 million in 2005, $1 billion in 2009, and projections of $7 to $10 billion by 2018. Along the way, it has turned Cephalon into a top-10 biotech. The Philadelphia-based firm has returned the favor by nearly tripling the pill's price, a move that scarcely made a dent in its off-label use, which accounts for 90 percent of all prescriptions.

Boosting the brain artificially is as commonplace as the consumption of caffeine and nicotine, but the off-label use of drugs for lifestyle enhancement remains officially off-limits. The medical establishment, the drug industry, and FDA have all strictly hewed to the time-honored disease model of healthcare. Yet after a decade in which consumer demand has risen to a din, Provigil—or, more specifically, Nuvigil, the new longer-acting version—may prove to be the tipping point, the right drug at the right time to shatter the old paradigm. Last year, Cephalon applied for the first "medical treatment" for "jet lag disorder," potentially opening the floodgates to the first neuro-lifestyle indication and a market of tens of millions of travelers.

"FDA is in a real quandary," says Anjan Chatterjee, professor of neuroscience at the University of Pennsylvania medical school. "If they open a regulatory door to cognitive enhancement, even a crack, the genie will be out of the bottle once. On the other hand, there's a larger public health imperative to do something because so many people are already using these drugs."