hematogen hematogen hematogen (russian: гематоге́н, gematogen; latin: haematogenum; greek: αιματογόνο, aimatogóno) is a nutrition bar which is notable in that one of its main ingredients is black food albumin, a technical term for cow's blood. other ingredients may vary, but they usually contain sugar, condensed milk and vanillin. bars of hematogen it is often considered to be a medicinal product, and is used to treat or prevent low blood levels of iron and vitamin b12 (e.g., for anemia or during pregnancy).