Abstract: The present invention relates to a peptide comprising the amino acid sequence QGLIGDIALPRWGALWGDSV (SEQ ID NO: 1). Inventors have tested in wild-type mice a single domain antibody directed against VWF and tagged with an albumin-binding peptide. After giving a single dose intravenously (50 microgram/mouse), VWF levels were increased 8-15 fold for at least 7 days, knowing that the half-life of VWF is about 2-3 hours in a mouse. Moreover, intravenous administration of VWF together with a sdAb fused to an albumin-binding peptide resulted in detectable levels of VWF at 48 and 72 hours after injection, whereas no VWF could be detected when injected in the absence of such sdAb fused to an albumin-binding peptide. Thus, these results show a very long-lasting effect of this new approach.