Also, the majority listed (though not the racetams) are stimulants, either related to amphetamines or e.g. ritalin. Those are generally understood to have troub

Also, the majority listed (though not the racetams) are stimulants, either related to amphetamines or e.g. ritalin. Those are generally understood to have troublesome side effects. Getting enough sleep, exercising regularly, and eating well will have a much bigger impact.