I have literally been using these for YEARS. There are zero side effects because it really is all natural. Now let's be clear - if I try to get 8 hours of sleep, I will probably wake up 2 times. For me, I use these so I can actually fall asleep. I can feel as tired as possible, but without taking a pill, I will be up all night unable to shut my brain off so I can sleep. Even after a night of drinking I still take one with no issues at all. These are seriously a life saver and I highly recommend them if you have problems falling asleep at night, but you don't want to wake up groggy or feeling like you were drugged.