Modafinil is a prescription medication used to promote wakefulness in individuals with certain sleep disorders. Modafinil is primarily prescribed to treat narcolepsy, obstructive sleep apnea (OSA), and shift work sleep disorder (SWSD). It helps to reduce excessive sleepiness and improve wakefulness. The exact mechanism of action of Modafinil is not fully understood, but it is believed to work by altering the levels of certain neurotransmitters in the brain that regulate the sleep-wake cycle, such as dopamine.