Abstract: A dispenser pump and cartridge forming a single unit which can be discarded after use includes a hollow pump body with an admission valve having flexible lips which separate at the time of use under the action of a pressure gradient established within the product to be dispensed. The pump body also has a delivery valve with a flexible tubular skirt which is inwardly deformable and capable of moving locally away from an annular sealing lip, thus permitting downward escape of a dose of product. Subsequent re-closing of the skirt prevents any upward admission of external air.