Difference Between Ferrous Gluconate and Ferrous Sulfate

Ferrous Gluconate vs Ferrous Sulfate

Iron is a metal in the d block with the symbol Fe. It is one of the most common elements forming the earth and has large amounts in the inner and outer core of the earth. It is the fourth most common element in the earth’s crust. Iron has oxidation states ranging from −2 to +8. Among these +2 and the +3 forms are the most common. +2 Oxidation form of iron is known as ferrous and +3 form is known as ferric. These ions are in the form of ionic crystals, which are formed with various anions. Iron is needed for biological systems for various purposes. For example in humans, ferrous is found as a chelating agent in hemoglobin. It is also important for the chlorophyll synthesis in plants. Hence, when there is a deficiency of this ion, biological systems show various diseases. Ferrous gluconate and ferrous sulfate are two ionic compounds that can be given as ferrous supplements to overcome iron deficiencies in living systems.

Ferrous Gluconate

One of the iron salts of gluconic acid is known as ferrous gluconate. The carboxylic acid group of the gluconic acid reacts with ferrous to produce this salt. Two gluconate ions are interacting with the ferrous ion when producing this salt. It has the molecular formula of C12H24FeO14. The molar mass of the compound is 448.15. Ferrous gluconate has the following structure.


This is a solid, which has a light yellow to brown/black appearance and a slight caramel odor. Ferrous gluconate is soluble in water. It is used as an iron supplement to the body. In the market, ferrous gluconate is marketed under the brand names like Fergon, Ferralet, and Simron. For diseases like hypochromic anemia, which is caused due to the lack of iron in the body, ferrous gluconate is given. Further, ferrous gluconate is used as a food additive.

Ferrous Sulfate

Ferrous sulfate is an ionic compound with the chemical formula FeSO4. It may exist in different crystal types depending on the amount of water molecules attached. It has the anhydrous form, monohydrate, tetrahydrate, pentahydrate, hexahydrate and heptahydrate forms. Among these, the blue, green color heptahydrate form is the common. Monohydrate, pentahydrate and hexahydrate forms are relatively rare.  Other than the blue, green color crystals, other forms of ferrous sulfate are mostly white colored crystals.  When heated the hydrated crystals loose water and become anhydrous solid. Upon further heating, it is decomposed into sulfur dioxide, sulfur trioxide and iron(III) oxide (reddish brown color). They are odorless crystals. Ferrous sulfate readily dissolves in water and, in that case, ferrous ion forms the hexa aqua complex, [Fe(H2O)6]2+. Ferrous sulfate is used to treat the conditions of iron deficiencies like iron deficiency anemia. Not only for humans, it is also added to plants, as well. In conditions like iron chlorosis, where plant leaves become yellow, pale color ferrous is given.  Other than that, it is used as a precursor to synthesize other compounds. Since it is a reduction agent, it is used for redox reactions, as well.


What is the difference between Ferrous Gluconate and Ferrous Sulfate?

• In ferrous gluconate, ferrous anion is combined with an organic anion. In ferrous sulfate, the anion is inorganic.

• Ferrous gluconate is a large compound compared to ferrous sulfate.

• Ferrous sulfate is abundant in nature compared to ferrous gluconate.

• When given as a supplement, ferrous gluconate is absorbed to our bodies much more than ferrous sulfate.