I used them several yrs ago and they make me nervous and drowsy. i was a wreck.
I think the caffine we get from coffee is more usable because we drink it slow over 30 minutes - an hour. Those pills could be disolving in your stomache quick giving you the full blast of caffine all with in 10 minutes or or so.
if for some reason, you want to keep using them maybe break in half and take the other part 3 hrs later???