A popular nootropic that is well-known for improving alertness and cognitive function is Modalert 200.  In addition to its medical applications, Modalert 200 is well-liked by professionals, students, and business owners who want to focus better, remember things better, and stay up longer.  When taken orally, it has effects that persist for up to 12 hours and begins to operate within 1-2 hours.  Despite its effectiveness, users should speak with their doctor before using it because it may have adverse effects or interact with other medications.