The usual duration of Modalert 200 mg is 10 to 15 hours, contingent on tolerance, metabolism, and other variables. Its effects might last all day long because its main function is to encourage alertness and attentiveness. The majority of people discover that the effects peak two to four hours after taking the dose and then gradually lessen in strength over time. The duration of Modalert is often adequate to sustain alertness throughout waking hours for people taking it for disorders like narcolepsy or shift work sleep disorder. It's crucial to refrain from taking it too late in the day, too, as its long-term effects may disrupt sleep cycles.