The effects of the modafinil-containing medication Modalert on the brain are complicated and not entirely known. When used as directed, modafinil is usually regarded as safe, however, there are some possible drawbacks. Tolerance, dependency, and possible changes in brain chemistry may result from prolonged usage. Individual reactions may differ, however, since research on its impact on brain health is still underway. Modalert must be used under medical supervision, recommended doses be followed, and any problems be discussed with a healthcare provider.