Modafinil

Modafinil, sold under the brand name Provigil among others, is a central nervous system (CNS) stimulant medication used to treat sleepiness due to narcolepsy, shift work sleep disorder, and obstructive sleep apnea. It is sometimes prescribed off-label for treating ADHD. While it has seen off-label use as a purported cognitive enhancer to improve wakefulness, in animal and human studies the research on its effectiveness for this use is not conclusive. Modafinil is taken by mouth.