For most people, Waklert 150 mg lasts 10 to 12 hours. Usually starting 30 to 60 minutes after consuming it, the effects peak in terms of alertness 2 to 4 hours later. Some people may experience remaining alertness into the evening due to armodafinil's rather lengthy half-life (about 12 to 15 hours). Depending on sensitivity, dose, metabolism, and whether food is consumed, duration can change. For narcolepsy, shift work sleep disorder, and sleep apnea-related drowsiness, Waklert 150 is frequently recommended. It is often used in the morning to prevent sleeplessness, unless a healthcare provider instructs you differently.