Modafinil promotes wakefulness and is used to treat excessive daytime sleepiness caused by narcolepsy, obstructive sleep apnea (OSA), or shift work sleep (SWS) disorder.

Modafinil does not treat the underlying disorder, it only makes people feel more awake.
Modafinil does not take the place of other treatments for narcolepsy or OSA. These should be continued while you are taking modafinil.
Modafinil's exact mechanism of action is unclear. However, it's believed to work by affecting brain chemicals that regulate sleep and wakefulness. While similar to stimulants like amphetamine and methylphenidate, modafinil has a different chemical structure. Modafinil belongs to the drug class called CNS stimulants.

Modafinil is classified as a Schedule IV (4) controlled substance due to its potential for misuse and dependence. Misuse of modafinil is illegal and harmful and you should always keep it in a safe place and never share it with others. Tell your doctor if you have a history of substance abuse.

Modafinil gained FDA approval on December 24, 1998, under the brand name Provigil. Modafinil is available as a generic and under the brand name Provigil.