The exact mechanism of Provigil is not clearly determined. However, in vitro studies have known have revealed that Modafinil, the active constituent, inhibits the reuptake of dopamine by binding to the dopamine reuptake pump. This enhances the levels of extracellular dopamine. Modafinil triggers glutamatergic circuits during inhibition of GABA. In simple terms, it acts on that area of the brain that is responsible for controlling sleep and wakefulness by increasing the levels of certain endogenous substances called neurotransmitters that are necessary to remain awake.
The effect of this medicine can be seen within 20 to 60 minutes post oral consumption. The action of this medicine can last for five to ten hours on an average.