Filgrastim is a medication that stimulates the production of white blood cells, specifically neutrophils, in the bone marrow. It is commonly used to help patients undergoing chemotherapy or those with certain blood disorders, as these conditions can lead to low white blood cell counts, increasing the risk of infections. This drug is a recombinant form of granulocyte colony-stimulating factor (G-CSF) and is administered through injection. By enhancing the body’s ability to produce neutrophils, Filgrastim helps improve the immune response and reduce the duration of neutropenia, a condition characterized by an abnormally low level of neutrophils.