The real Limitless drug

Modafinil (Provigil in the United States) was first approved by the FDA in 1998 for the treatment of narcolepsy, but since has become better known as a nootropic, a “smart drug,” especially among entrepreneurs, says New York magazine.
 
Rumored to be the model for the fictional pills in the movie Limitless, no scientist has conducted a study of its long-term effects on healthy brains yet. At the very least, doctors have warned that modafinil can bring about sleep deprivation.