Suggest Medicines That Contain Neuro Energisers

Sir,

i'm 23 years old & my height is 5 feet 8 inches.

Doctor has recommended me to take a medicine which contains neuro energisers but i have not observed any difference from 3 months.

Since last five years i'm totally unable to concentrate and focus on my studies.

Sir how i can overcome this problem.

Please provide useful suggestions.

Further i'm preparing for national level exam but i think if the problem persists i will make it this time.

Please help sir...