Abstract: A process is presented for reducing the detrimental influence of certain proteases on recombinant human protein and polypeptide production in a cell culture, which comprises adding an inhibitor of metal-dependent proteases or chymotrypsins to the cell culture medium. The cell culture medium for cultivating cells expressing and secreting a biologically active recombinant human polypeptide contains an inhibitor of metal-dependent proteases or chymotrypsins, or a combination thereof. Recombinant factor VIII which has been produced in a cell culture medium according to the present process is useful for the manufacture of a medicament for administration to a patient having the symptoms of hemophilia A and for treatment of hemophilia A by administration of a therapeutically effective amount of recombinant factor VIII.