Modvigil 200 has been shown to greatly improve concentration, attention, and mental alertness, particularly in people who are fatigued or sleep deprived. It is often given for narcolepsy and shift work sleep disorder, although many people use it off-label to improve cognitive function. Modvigil 200mg, by increasing brain chemicals associated with alertness and focus, can help users be productive for longer lengths of time—typically 10 to 12 hours. While many people experience increased attention and drive, the results vary by individual. It should be used responsibly under medical supervision, as potential side effects include insomnia, anxiety, headaches, or irritability with prolonged use.