You shouldn't have any issues, unless you're way overdosing them. Which you'd likely be able to tell by the warm/burning sensation, that Tex mentions, in your upper stomach/lower sternum area.Using them can also help "train" your body to ramp up it's natural production of digestive enzymes.If you aren't having digestive issues (cramping, diarrhea, constipation, bloating, undigested food particles in your dook, etc), then you probably don't need them. How will you know they're helping? The issues will lessen/go away.