Baruch Elad, chairman of the Israeli Society for Sleep Research at the Israel Medical Association, said: “Provigil is activated approximately 8-12 hours after medicine intake. It helps maintain wakefulness while not affecting the ability to sleep. Taking one or two tablets during the day (or at night for nightshift workers) when people experience excessive fatigue, significantly improves their level of wakefulness, their functioning and their ability to concentrate. Provigil was proved to be safe and effective in a large number of clinical studies.”