I am on Amphetamine salts for my ADD and they have given me terrific improvement in a lot of skills that require deep concentration. I do suffer from some adverse effects like insomnia, some immunity to the drug, etc but I feel that they are worth it. I plan to continue taking it until I find some thing better. I have tried almost all kinds of drugs available in the market that have provided comparable effectiveness. The D Isomer is better for me but I have heard that the L Isomer is equally powerful in dopaminergic and less effective in norephrine highs.