The present invention relates to a method and system for dosing a pharmaceutical product in a packaging machine having at least one volumetric dosing unit with a dosing chamber. The system check-weighs the volumetrically dosed product with appropriate speed and is integrated into a filling or packaging machine. In accordance with the invention, a volume of a first pharmaceutical component is metered and weighed before being introduced into a package. The procedure is repeated with a second pharmaceutical component. The package containing the components is then weighed. Advantageously, accuracy and precision of the amount of the weighed components can be monitored with the present invention to secure the quality of the pharmaceutical product.