Modafinil, the active constituent present in Provigil is an FDA approved drug. It is available for sale at a local pharmacy or online medical store. It is a smart drug. Its molecular formula is C15H15NO2S and its molecular weight is 273.35. It is a habit-forming drug belonging to a class of drugs known as wakefulness-promoting agents/ Psychoanaleptic. The exact mechanism of Modafinil is not clinically established. It has more than a few important effects on the brain. Modafinil is believed to improve the levels of numerous neurotransmitters in the brain such as orexin, dopamine, histamine, and norepinephrine. Orexin is responsible for regulating sleep-wake cycles, dopamine improves focus, which helps to stay attentive for a long duration, and norepinephrine improves mental energy. The action of Provigil medication is seen within 20 to 60 minutes post oral administration, while its effect continues for a duration of about five to ten hours.