Anemia is a condition where your body does not have enough red blood cells to carry oxygen around your body. If you do not have enough iron from the foods you eat (because of poor nutrition or poor absorption of the mineral), your body will produce fewer red blood cells and can cause anemia. Ironfast Injection is an iron replacement product. It can boost your levels of red blood cells and reduce the symptoms of anemia such as tiredness and weakness. This medicine is given as an injection by a doctor or nurse. You should not have this medicine if your anemia is not caused by a lack of iron.