Feosol is a brand name for ferrous sulfate, which is an iron supplement. There are several synonyms for feosol available in stores, including ferrous gluconate, ferrous fumarate, and ferrous sulfate heptahydrate. These iron supplements are designed to treat or prevent iron deficiencies or anemia. Iron is vital to the body as it helps transport oxygen throughout the body. However, iron deficiencies can cause an array of health problems, including fatigue, weakness, and shortness of breath. Therefore, it is essential to take an iron supplement if your body is not getting enough iron from your diet. Consult with a healthcare provider before starting any new supplements.