The present invention provides a method of administering porcine B-domainless factor VIII (OBI-1) to a patient having factor VIII deficiency to provide more rapid and effective protection against bleeding episodes, compared to formerly available methods, or to provide more effective protection to such patients during non-bleeding periods. This invention is based on the discovery that the recombinant B-domainless porcine fVIII, termed OBI-1, has greater bioavailability compared to the natural porcine fVIII partially purified from porcine plasma, termed HYATE:C. Therefore, the inventive method employs lower unit doses of OBI-1, including, alternatively, omission of antibody-neutralizing dosage, or has longer intervals between the administration, compared to HYATE:C, to provide equivalent protection in patients having fVIII deficiency. The invention further provides pharmaceutical compositions and kits containing OBI-1 in combination with a pharmaceutically acceptable carrier, that are useful for treating patients in need of fVIII more effectively.