Modvigil (modafinil) can keep you awake and alert for about 10 to 12 hours, sometimes up to 14 hours in certain individuals. It usually starts working within 30–60 minutes, with peak effects around 2–4 hours. The duration depends on your metabolism, dose, and sleep condition. While it reduces sleepiness and helps maintain wakefulness, it doesn’t replace actual sleep. Taking it late in the day can interfere with nighttime rest.
