Modafinil Modafinil, sold under the brand name Provigil is used to treat sleepiness caused due to narcolepsy, obstructive sleep apnea and shift work sleep disorder. It is a cognitive enhancer that promotes wakefulness in a person by affecting a certain substance in the brain that controls the sleep/wake cycle. Modafinil use will not cure these sleep disorders and may not get rid of all your...