Modalert 200 is a brand name for the medication Modafinil, commonly used to treat conditions like narcolepsy, sleep apnea, and shift work sleep disorder. It's a wakefulness-promoting agent that helps people stay awake and alert during their waking hours. However, it's essential to use it under a doctor's guidance, as misuse or improper dosage can lead to side effects and potential health risks. If you have any concerns or questions about using Modalert 200, it's best to consult a healthcare professional.