Bottles containing Moroctocog alfa (trade name ReFacto) blood clotting factor VIII concentrate, used to treat haemophilia. These two preparations, of different concentrations, are reconstituted before intravenous injection. Haemophilia is a hereditary disorder in which the blood clots very slowly, due to a deficiency in one of the blood coagulation factors. FVIII, also known as anti-haemophilic factor (AHF), is an essential blood clotting agent in humans.