Buying Modvigil online is suitable for people of all ages; students use it to improve concentration before tests, and employers use it to meet high expectations and deadlines. The drug is mainly used to treat serious sleeping conditions such as narcolepsy. However, a licenced doctor should prescribe the dose based on the patient's condition. For narcolepsy, the usual dose is 200mg, taken once once in the morning. If you're using it to treat a sleep disturbance for work or school, take 200 mg before you start.