in my memory and concentration. i haven't noticed any side effects to my body or any changes to my sleep. i am sure if i had taken them more then once a day, i would see a great improvement, but i really wanted to spread these out over the three months. i would rather have a slight improvement over a few months then a great improvement over one month. i am not sure if the memory improvement would fade after taking the last of the pills as i haven't taken them all yet. i am hoping though that it is an improvement that will stick around and not something that 