Disclosed is a medical fluid connector configured to receive and dispense medical liquid. The medical connector can be structured to include an initial stage in which medical liquid is infused into the connector and dispensed out of the connector essentially unchanged. The medical connector also can be structured to include a subsequent stage in which medical liquid is not infused into the connector and a volume of therapeutic liquid is dispensed out of the connector. The therapeutic liquid can include a portion of the volume of the medical liquid that was infused into the connector in the initial stage plus a therapeutic additive.