In "Sleep, Waking, and Neurobehavioral Performance", published in Frontiers in Bioscience in September 2003, Naomi L. Rogers, Jillian Dorrian, and David F. Dinges report that modafinil shows fewer adverse side effects than stimulants like amphetamines. These negative consequences of amphetamines include bodily agitation and trouble sleeping when the patient is allowed to sleep. The authors admit that scientists still do not understand the mechanism of Provigil inside the body.

Studies have shown that the Provigil improves reaction time in sleep-deprived people. It also enables people to perform better on tests of neurological behavior, including grammatical reasoning and visual search. Many of these tests were done in simulated military combat situations, and the test patients report feeling less sleepy when they have taken the drug.

One aspect of studies like these is that there is both an objective and a subjective component to cognitive performance, and both are measured in sleep studies. Provigil appears to improve wakefulness in both components.

Compared to amphetamines, Provigil results in less of a disturbance in sleep during the “rebound” period after the drug wears off and the person resumes natural sleep. The duration of required recovery sleep is also less. Negative effects of the drug include decreased efficiency of communication, and possibly subjective estimates of cognitive ability (by the person on the drug.)

Neuroscience research suggests that modafinil affects "gap junctions" between neurons. The electric aspects of the brain are still being determined.

Provigil’s full name is 2-[(diphenylmethyl)sulfinyl] acetamide. Molecular formula is C15H15NO2S.

Modafinil’s mechanism of action is undetermined, although it is known to be different from that of central nervous system stimulants. It does not act as a direct or indirect dopamine receptor agonist. It does not bind to receptors for dopamine, serotonin, GABA, or norepinephrine uptake.

New research from South Korea shows that in narcoleptic patients, modafinil use increases cerebral blood flow in the bilateral prefrontal cortices and decreases blood flow in the left mesio/basal, temporal, bilateral occipital areas, and in the cerebellum.

Mechanism of Provigil in the body

Provigil has a safer side-effect profile than other psychostimulants