Device for packaging and dispensing a product, notably a cosmetic product, comprising a container provided with at least one variable volume compartment containing said product, and a dispensing head comprising: - a mounting base fixed to the container, - an internal piston movable in translation along a displacement axis (Y-Y') and delimiting first and second pumping chambers (38, 40) inside said base, - at least first and second inlet holes (42, 44) for communicating respectively the first and second pumping chambers with the container compartment, and at least first and second inlet valves (50, 58) respectively closing the first and second inlet holes (42, 44) in a leak-tight manner, characterized in that the dispensing head further comprises: - at least one actuating rod extending through the pumping chambers and the piston and extending while protruding on either side of the mounting base, said rod internally delimiting a first inlet channel in communication with a first outlet hole of the dispensing head and a second inlet channel separate from said first channel and in communication with a second outlet hole of said head, and - at least first and second through holes (74, 76) formed on the actuating rod and respectively opening out in said first and second inlet channels, - wherein the actuating rod is axially movable and provided with stopping means (78, 80) capable of allowing said rod to slide relative to said piston between a first end position in which the first through hole is obstructed by the piston and the second through hole connects the second supply channel with the second pumping chamber, and a second end position in which said first hole connects the first supply channel with the first pumping chamber and said second hole is blocked by the piston. - a mounting base fixed to the container, - an internal piston movable in translation along a displacement axis (Y-Y') and delimiting first and second pumping chambers (38, 40) inside said base, - at least first and second inlet holes (42, 44) for communicating respectively the first and second pumping chambers with the container compartment, and at least first and second inlet valves (50, 58) respectively closing the first and second inlet holes (42, 44) in a leak-tight manner, characterized in that the dispensing head further comprises: - at least one actuating rod extending through the pumping chambers and the piston and extending while protruding on either side of the mounting base, said rod internally delimiting a first inlet channel in communication with a first outlet hole of the dispensing head and a second inlet channel separate from said first channel and in communication with a second outlet hole of said head, and - at least first and second through holes (74, 76) formed on the actuating rod and respectively opening out in said first and second inlet channels, - wherein the actuating rod is axially movable and provided with stopping means (78, 80) capable of allowing said rod to slide relative to said piston between a first end position in which the first through hole is obstructed by the piston and the second through hole connects the second supply channel with the second pumping chamber, and a second end position in which said first hole connects the first supply channel with the first pumping chamber and said second hole is blocked by the piston.