Modafinil is a wakefulness-promoting substance found in the prescription drug Modalert 200. It is mostly used to treat narcolepsy, shift work sleep disorder (SWSD), and obstructive sleep apnea (OSA), which all induce excessive drowsiness. During waking hours, Modalert 200 helps increase mental clarity, attention, and alertness by activating the brain. Though not FDA-approved, it is occasionally used off-label to improve cognitive function. By changing neurotransmitters like dopamine and norepinephrine, modalert promotes alertness without having the jittery side effects of conventional stimulants. Because of the possible adverse effects, which include anxiety, sleeplessness, and headaches, it should only be taken under medical supervision.