Modalert 200 is therefore often advised to be taken in the morning or early afternoon. For advice on when to take the drug or possible substitutes, speak with your healthcare practitioner if you have trouble falling asleep or have poor sleep quality while taking it. Modalert 200 too late in the day might have an adverse effect on sleep quality. It may make it difficult to fall or remain asleep, resulting in insomnia or other sleep disorders, because it encourages vigilance and attentiveness. Taking Modalert too soon to bedtime might throw off your sleep schedule because its effects usually last 10 to 12 hours.