It kind of depends on the specific bearded dragon, how much they eat, and how often they eat. My bearded dragon (who is a little over six months old now) goes once every day. Typically, younger bearded dragons will go daily, some twice a day. As they get older, they may go less often. If you notice they are not defecating regularly according to their own personal schedule, then there could be a problem. More than a few days without defecating (associated with other symptoms, such as lack of appetite or energy, etc.), and anything longer than a week may indicate some problems.