Buy Provigil Online , also known as modafinil, is frequently used to treat narcolepsy, a persistent rest disorder characterised by excessive daytime sleepiness and an abrupt onset of sleep. Additionally, it is used to treat shift work rest disorder and obstructive sleep apnea, two other conditions related to poor sleep. One of Provigil main functions is to increase sharpness in people who struggle to maintain their awareness throughout the day. It functions by affecting specific neurotransmitters, specifically dopamine, in the frontal cortex.