Circuits, devices and methods for achieving fast changes in voltage regulator outputs. In some embodiments, a voltage regulation system can include a voltage regulator configured to receive an input voltage Vin and generate an output voltage Vout at an output node, and to transition Vout between V1 and V2. The voltage regulation system can further include a transition circuit coupled to the output node. The transition circuit can include a first voltage source that is switchably coupled to the output node and configured to provide a voltage associated with one of the V1 and V2 voltages to the output node during at least the transition of the voltage regulator. The voltage provided by the first voltage source can be substantially equal to one of the V1 and V2 voltages.