Narcolepsy, sleep apnea, and shift work sleep disorder are among the diseases that are frequently treated with Modvigil, a brand of modafinil, a wakefulness-promoting drug. Depending on personal characteristics, including metabolism, age, body weight, and general health, the effects of a 200 mg dosage of Modvigil usually last 12 to 15 hours. About two to four hours after consumption, the drug's blood concentration reaches its peak. It is typically used in the morning to prevent disrupting sleep at night because of its long-lasting effects. Insomnia or irregular sleep patterns may result from taking Modvigil too late in the day. When using Modvigil, always adhere to your doctor's recommended dosage and usage guidelines for optimal effectiveness and the fewest possible negative effects.