Protocols for dose ranging trials in healthy volunteers or patients can be described by the combination of an experimental design and one or more decision rules. Generally, the doses are chosen on the basis of an up-and-down method, until the maximum tolerated (affecting one or more physiological parameters) and the minimum effective doses are found. Despite the large number of possible protocols there is no standard for the description of the experimental design or the decision rule(s). We propose a series of variables that can be used to facilitate data collection and that can adequately and uniquely characterize most dose ranging protocols.