The Clotting Process

According to the Centers for Disease Control and Prevention, VWD is the most common bleeding disorder, affecting up to 1% of the general population.1 In order to understand VWD and its treatment, it helps to know how blood coagulation works and how Humate-P helps clots form properly.

Here is a general description of the blood-clotting process:

  • When your body is injured and there is damage to the blood vessels, a plug, or blood clot, forms to stop the bleeding.2
  • A clot is made up of platelets that circulate in your blood, and fibrin that forms to hold the platelets together.2
  • The process that causes clots to form is called clotting.3

For clotting to work, certain protein factors in your blood must work together. One of these factors is von Willebrand factor (VWF), a protein in the blood that is critical to the clotting process.3

Von Willebrand factor and bleeding

VWF is an important part of stopping bleeding after an injury. This is why people with VWD have excessive bleeding.

  • VWF binds with platelets, causing them to stick together where the injury has occured.
  • VWF also stabilizes and protects another factor that’s necessary for clots, factor VIII (FVIII).
  • If a person can’t make enough VWF, or if their VWF isn’t working properly, it’s called von Willebrand disease.

How your body clots normally vs. clotting in VWD2

Important Safety Information

Antihemophilic Factor/von Willebrand Factor Complex (Human), Humate-P® is approved to treat and prevent bleeding in adult patients with hemophilia A (classical hemophilia). Humate-P also treats spontaneous or trauma-induced bleeding episodes in adults and children with von Willebrand disease (VWD) and prevents excessive bleeding during and after surgery in patients with mild, moderate or severe VWD. Humate-P is not known to prevent spontaneous bleeding episodes.

Do not take Humate-P if you have had extreme sensitivity or an allergic response to antihemophilic or von Willebrand factor preparations. Your doctor will monitor you for events related to abnormal blood clotting.

Humate-P is made from human blood and could contain infectious agents. The risk that these agents may transmit disease cannot be completely eliminated, but has been reduced by screening plasma donors and testing donated plasma for certain viruses, and by inactivating and/or removing viruses during manufacturing.

In studies, more than 5% of patients reported the following adverse reactions to Humate-P: allergic/anaphylactic reactions, including hives, chest tightness, rash, itching, and swelling. The most common adverse reactions after surgery were bleeding at the wound or infusion site, and nosebleeds.

Please see full prescribing information.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit or call 1-800-FDA-1088.

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© CSL Behring 2019. The product information on this site is intended for US residents only. HUM / 10-11-0010(1) 8/2015


  1. Centers for Disease Control and Prevention (CDC). Facts about von Willebrand disease. Published March 20, 2015. Accessed April 27, 2015.
  2. Hoffman M, Monroe DM. Coagulation 2006: a modern view of hemostasis. Hematol Clin N Am. 2007;21:1-11.
  3. National Heart, Lung, and Blood Institute. The Diagnosis, Evaluation and Management of von Willebrand Disease. National Institutes of Health; 2007. NIH Publication No. 08-5832.