For treating narcolepsy or shift work sleep disorder, Buy Modalert 200 (modafinil) is usually used once in the morning. Users find 100 to 200 mg beneficial for cognitive improvement, but start low to test tolerance and effects. The highest suggested daily dosage is 400 mg, although exceeding it might cause headaches, sleeplessness, anxiety, and gastrointestinal difficulties. What works for one person may not work for another using Modalert. Before taking Modalert, visit a doctor to make sure it’s right for you and to address any drug interactions or health issues.