Some scientists have predicted that

Some scientists have predicted that healthy adults and children may one day take drugs to improve their intelligence and intellectual performance. A research group has suggested that such drugs might become as common as coffee or tea within the next couple of decades.
To counter this, students taking exams might have to take drugs tests like athletes. There are already drugs that are known to improve mental performance, like Ritalin, which is given to children with problems concentrating. A drug given to people with trouble sleeping also helps people remember numbers.
These drugs raise serious legal and moral questions, but people already take vitamins to help them remember things better, so it will not be a simple problem to solve. It will probably be very difficult to decide at what point a food supplement becomes an unfair drug in an examination.