I received Centrophenoxine at a discounted price in exchange for an honest and unbiased review. I have difficulty concentrating due to medications I am taking but since I started taking Centrophenoxine, my concentration has improved signicantly. I am even able to sit and read a book for hours now which I haven't been able to do for years. It's amazing! I suggested my boyfriend try it as well b/c he has ADHD and he's finding it easier to concentrate at work.