I've been taking AREDS 2 for about a year and have never experienced an upset stomach after taking the pill. I recently started taking one in the morning and one in the evening which I think is the dosage recommended on the packaging. I have a friend in his mid 80s who was involved in the Bausch and Laumb study for AREDS 2 and he still receives free pills from them. He's never had any stomach issues either. I did find that it is a known side effect that you should discuss with your doctor if you are having it.