Iron infusion may be a procedure during which iron is delivered to your body intravenously, meaning into a vein through a needle. This method of delivering medication or supplementation is additionally referred to as an intravenous (IV) infusion. Iron infusions are usually prescribed by doctors to treat iron deficiency anemia. Iron deficiency anemia is usually treated with dietary changes and iron supplements that you simply absorb pill form. In some cases, though, doctors may recommend iron infusions instead. Results After 3 months of iron therapy, significant hemoglobin (Hgb) increase was observed in 30 of 33 patients. Weight gain and Hgb increase haven't been found in three patients. Weight gain associated with iron therapy may be a common problem in female patients with iron deficiency anemia.