Buy Modafinil Online get fast delivery with free shipment charges. Provigil is a brand name for the medication modafinil, which is used to treat excessive daytime sleepiness associated with narcolepsy, obstructive sleep apnea, and shift work sleep disorder. It is also sometimes used off-label to enhance cognitive function and improve focus and alertness in individuals without sleep disorders. Modafinil works by affecting certain neurotransmitters in the brain, specifically dopamine, norepinephrine, and histamine.