The effect of human lactoferrin on the arrest of experimental hemorrhagic anemia consequences was studied in rats. After six blood losses (days 1-4 and 7-8 of the experiment), the rats developed acute anemia: hemoglobin concentration decreased to 59% of the initial level, serum iron level decreased 3-fold. Intraperitoneal injections of lactoferrin (10 mg/day) for 4 days starting from day 7 led to an increase in hemoglobin level to 109% and of serum iron to 125% on day 14. In controls, hemoglobin level on day 14 was 70% and iron content 49% of the initial level. Ferroxidase activity of ceruloplasmin in blood serum decreased after 5 blood losses returned to normal only in rats receiving lactoferrin. The results indicate that lactoferrin modified ceruloplasmin activity in vivo, promoting normalization of iron metabolism.