Healthy Living

What Is Ferrous Sulfate?

Ferrous Sulfate Folic Acid

Ferrous sulfate is an essential mineral and a type of iron used for the treatment of iron deficiency anemia (IDA). When a person lacks iron, symptoms such as tiredness, shortness of breath, and decreased physical performance may be experienced.  

Low levels of iron in the body can be treated by taking ferrous sulfate. Some natural sources of iron are oatmeal, dried peaches, asparagus, beans, nuts, and lean red meat. Iron absorption can be increased by vitamin C, which can be found in citrus fruits and fresh vegetables. Ferrous sulfate is a compound of iron. Hemoglobin helps carry oxygen and myoglobin helps store oxygen in muscle cells.

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Ferrous sulfate is usually taken by mouth. It is available in the form of tablets and liquid. The tablets are available in the strengths of 300 mg and 324 mg.

How to Take Ferrous Sulfate

Ferrous sulfate should be taken on an empty stomach an hour before or two hours after meals. Antibiotics or antacids should not be simultaneously taken with ferrous sulfate. Drink one full glass of water when taking ferrous sulfate. 

Swallow the pill whole and do not chew, crush, break, or open ferrous sulfate capsules and extended-release tablets. Breaking the pill may release too much of the drug at one time. 

When taking the liquid form, make sure to shake the suspension before measuring a dose. The dose should also be measured using a medicine cup or a special measuring spoon that comes with the medicine. Ask your pharmacist for a dose-measuring device if you do not have one. 

Taking ferrous sulfate can also cause a temporary discoloration or staining of the teeth. To prevent teeth staining, mix water or fruit juice to the liquid form of ferrous sulfate and drink it through a straw. Cleaning the teeth using baking soda once a week may also help prevent any discoloration. 

Keep ferrous sulfate away from heat and moisture. Store it at room temperature. 

Side Effects

The side effects of ferrous sulfate may include:

  • An upset stomach
  • Dark or black stools
  • Constipation
  • Temporary discoloration of the teeth 

Seek immediate medical attention if you develop any of the following signs of an allergic reaction after taking ferrous sulfate: 

  • Swelling of the face, tongue, throat, or lips
  • Difficulty breathing
  • Hives

Things to discuss with your doctor

If you have any of the following conditions, discuss with your doctor whether you should take ferrous sulfate:

  • Iron overload syndrome
  • Hemolytic anemia
  • Thalassemia or porphyria
  • Alcohol abuse and alcoholism
  • Regularly receiving blood transfusions

Ferrous Sulfate, Iron Deficiency, and Anemia

Insufficient iron in the blood causes anemia. The body needs iron to produce hemoglobin, a protein molecule that helps the RBCs carry oxygen from the lungs to all parts of the body. 

Anemia can make a person feel exhausted since RBCs carry oxygen everywhere. Usually, the symptoms are unnoticeable when anemia is mild. However, a person may look tired, weak, pale, irritable, and have headaches. Some people may have chest pain and an irregular heartbeat.

Anemia can be caused by a number of reasons. They include:

Doctors may prescribe iron supplements for people who are deficient in vitamin B12. Iron deficiency is the major cause of anemia. It either occurs due to a lack of iron absorption or due to blood loss. The doctor may suggest certain dietary changes and taking ferrous sulfate supplements. 

Most adults take iron supplements in the form of a pill. Ferrous sulfate may also be intravenously administered or through injections if patients are severely anemic or if the pills are intolerable. Within a few days, the symptoms of anemia tend to improve. However, in some cases, ferrous sulfate supplements may be taken for several months to adequately replenish the iron reserves in the body.

10 Reasons Why You May Need Ferrous Sulfate Supplements

  1. Iron deficiency anemia -  This condition occurs when there is an insufficient iron in the RBCs. Without normal levels of iron in the body, the RBCs cannot provide enough oxygen to the cells and tissues. 
  2. You are pregnant - Women who are not pregnant or breastfeeding need a daily iron intake of 15-18 mg. However, those who are pregnant need more iron. The recommended daily iron intake for pregnant women is 27 mg. 
  3. You have a baby - When your baby is 6 months old, iron-fortified foods should be added to your baby's diet. While babies are in the womb, they build up stores of iron from their mothers. However, these iron stores are depleted during their six months of life when they are breastfeeding. 
  4. During menstruation - The rate of anemia is higher in females than males since menstruation tends to deplete iron stores in the body. Ethnicity is also one of the risk factors for anemia, according to some research studies. 
  5. Exercise - Female athletes tend to have an increased risk of developing an iron deficiency than male athletes. Although the exact reason is unknown, researchers suggest that athletes may require more RBCs to carry oxygen, so that they can keep exercising. 
  6. Regular blood loss - Extra iron is needed by people who experience an excessive loss of blood. In most cases, those who have gastrointestinal bleeding and people who regularly donate blood are at risk. 
  7. You are on dialysis - Extra iron is needed by those who are on dialysis. A small amount of blood is also lost during the procedure. 
  8. Iron-depleting medications - The ability of the body to absorb iron is interfered by certain medications and can cause iron depletion.
  9. Attention deficit hyperactivity disorder (ADHD) - Researchers have also found that children with ADHD have low iron levels. Even ferritin, which is needed to store iron, is low in the body.
  10. ACE inhibitor-induced cough - ACE inhibitors are taken for a number of conditions. The chances of coughing tend to reduce in people who also take ferrous sulfate. 

Many people respond well when iron supplements are taken. Intravenous iron is needed when the iron level is very low. 


Gastrointestinal tract issues may arise if ferrous sulfate is ingested. If a large amount of ferrous sulfate is ingested by young children, it can cause the following:

  • Hematemesis (vomiting of blood)
  • Liver damage
  • Peripheral circulatory collapse

The toxicity varies with the salt. Usually, the salt solution causes irritation to the mucous membrane and is corrosive to the skin. Ferrous sulfate can cause irritation of the nose and throat if it is inhaled. It can also irritate the mouth and stomach if it is ingested. The eyes may become irritated when ferrous sulfate powder enters the eyes. 

Clinical Effects of Ferrous Sulfate

Iron overdose is one of the leading causes of iron poisoning in children below 6 years old. Iron is usually used as a prenatal or pediatric vitamin and as a mineral supplement to treat anemia. Most of the time, iron tablets tend to appear like candies, so unsupervised young children are particularly tempted to take a lot of it. In adults, an iron overdose often indicates a suicide attempt. 

Chronic development of an iron overload can also happen, particularly in patients who need multiple RBC transfusions. Such condition may develop in people with thalassemia, sickle cell disease, and myelodysplastic syndromes. When iron poisoning occurs, it causes severe symptoms, which include:

  • Gastrointestinal bleeding
  • Diarrhea
  • Vomiting
  • Lethargy
  • Shock
  • Acidosis
  • Seizures
  • Coma
  • Hepatotoxicity
  • Intestinal stenosis

Excess iron in the body may build up in the organs, such as the spleen, liver, and lymphatic system causing diabetes mellitus, liver cirrhosis, and pancreatic fibrosis. The symptoms include nausea, vomiting, irritability, and normocytic anemia. 

Other Uses of Ferrous Sulfate

  • Preparation of other iron compounds
  • Ink and ink pigment preparations
  • Printmaking and lithography
  • Wood preservative
  • Animal fodder
  • Wastewater treatment
  • Plaster and iron chloride production
  • Reducing the content of water-soluble chromates
  • Chlorosis
  • Alkaline soil treatment
  • Moss control
  • Preparation of alumina and iron oxide pigments
  • Leather tanning