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Ferrous sulfate

Generic name: ferrous sulfate (FARE us SUL fate)
Brand name: Feosol, Fer-In-Sol, Ferrousal, Slow Fe, Slow Release Iron, ...show all 23 brand names
Dosage forms: oral delayed release tablet (324 mg; 325 mg); oral elixir (220 mg/5 mL); oral liquid ((as elemental iron) 15 mg/mL; 300 mg/5 mL); oral tablet (200 mg; 325 mg); oral tablet, extended release ((as elemental iron) 45 mg; 160 mg)
Drug class: Iron products

Medically reviewed by Sanjai Sinha, MD. Last updated on Jul 7, 2021.

What is ferrous sulfate?

Ferrous sulfate is a type of iron. You normally get iron from the foods you eat. In your body, iron becomes a part of your hemoglobin and myoglobin. Hemoglobin carries oxygen through your blood to tissues and organs. Myoglobin helps your muscle cells store oxygen.

Ferrous Sulfate is an essential body mineral.

Ferrous sulfate is used to treat iron deficiency anemia (a lack of red blood cells caused by having too little iron in the body).

Warnings

Ask a doctor or pharmacist if it is safe for you to take ferrous sulfate if you have iron overload syndrome, hemolytic anemia (a lack of red blood cells), porphyria (a genetic enzyme disorder that causes symptoms affecting the skin or nervous system), thalassemia (a genetic disorder of red blood cells), if you are an alcoholic, or if you receive regular blood transfusions.

Seek emergency medical attention if you think you have used too much of this medicine, or if anyone has accidentally swallowed it. An overdose of iron can be fatal, especially in a young child.

Overdose symptoms may include nausea, severe stomach pain, bloody diarrhea, coughing up blood or vomit that looks like coffee grounds, shallow breathing, weak and rapid pulse, pale skin, blue lips, and seizure (convulsions).

Take ferrous sulfate on an empty stomach, at least 1 hour before or 2 hours after a meal. Avoid taking antacids or antibiotics within 2 hours before or after taking ferrous sulfate.

Ferrous sulfate is only part of a complete program of treatment that may also include a special diet. It is very important to follow the diet plan created for you by your doctor or nutrition counselor. You should become very familiar with the list of foods you should eat to make sure you get enough iron from both your diet and your medication.

Before taking this medicine

Ask a doctor or pharmacist if ferrous sulfate is safe to use if you have ever had:

  • iron overload syndrome;

  • a red blood cell disorder such as thalassemia; or

  • a condition for which you receive regular blood transfusions.

Ask a doctor before using this medicine if you are pregnant or breastfeeding.

Do not give ferrous sulfate to a child without medical advice.

How should I take ferrous sulfate?

Use ferrous sulfate exactly as directed on the label, or as prescribed by your doctor.

Take on an empty stomach, at least 1 hour before or 2 hours after a meal.

Measure liquid medicine carefully. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).

Swallow the tablet whole and do not crush, chew, or break it.

You may need to follow a special diet. Follow all instructions of your doctor or dietitian. Learn about the foods you should eat or avoid.

Store at room temperature, away from moisture and heat.

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. Get emergency medical help if a child has accidentally swallowed a tablet. An overdose of iron can be fatal to a young child.

Overdose symptoms may include severe vomiting, coughing up blood, bloody diarrhea, urinating less, thirst, dry skin, muscle cramps, dizziness, or fainting.

What should I avoid while taking ferrous sulfate?

Avoid taking other iron supplements. Do not take any vitamin or mineral supplements without asking a doctor or pharmacist.

Ferrous sulfate side effects

Get emergency medical help if you have signs of an allergic reaction to ferrous sulfate: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

  • severe stomach pain or vomiting;

  • cough with bloody mucus or vomit that looks like coffee grounds;

  • fever; or

  • bloody or tarry stools.

Common ferrous sulfate side effects may include:

  • diarrhea, constipation;

  • nausea, stomach pain;

  • green-colored stools; or

  • loss of appetite.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Ferrous sulfate dosing information

Usual Adult Dose for Iron Deficiency Anemia:

Initial dose: 600 mg/day ferrous sulfate (120 mg/day elemental iron) for 3 months
-Give in divided doses (1 to 3 times daily)

Usual Adult Dose for Anemia Associated with Chronic Renal Failure:

Initial dose: 1000 mg/day ferrous sulfate (200 mg/day elemental iron) orally in divided doses (1 to 3 times daily)

Comments:
-If goals are not met with oral iron after 1 to 3 months, consider IV iron supplementation.
-Smaller daily doses may be better tolerated.

Usual Adult Dose for Vitamin/Mineral Supplementation:

Initial dose: 1 tablet orally once a day

or

Initial dose: 30 to 90 mg/day ferrous sulfate (FeSO4) (6 to 18 mg/day elemental iron) orally, in divided doses (1 to 3 times daily)

51 and over: 25 to 40 mg/day FeSO4 (5 to 8 mg/day elemental) orally, in divided doses (1 to 3 times daily)

Usual Pediatric Dose for Iron Deficiency Anemia:

0 to 5 years: 15 to 30 mg/kg/day ferrous sulfate (FeSO4) (3 to 6 mg/kg/day elemental iron)
5 to 12 years: 300 mg FeSO4 (60 mg/day elemental)
12-18 years male: Two 300 mg FeSO4 (60 mg elemental) tablets orally daily
12-18 years female: 300 to 600 mg/day FeSO4 (60 to 120 mg/day elemental)
-Give in divided doses (1 to 3 times daily)

Usual Pediatric Dose for Vitamin/Mineral Supplementation:

Preterm infant (less than 37 weeks gestation), 0 to 12 months: 10 mg/kg/day ferrous sulfate (FeSO4) (2 mg/kg/day elemental iron)
0 to 6 months: 1 to 1.35 mg/day FeSO4 (0.2 to 0.27 mg/day elemental)
7 to 12 months: 35 to 55 mg/day FeSO4 (7 to 11 mg/day elemental)
1 to 3 years: 20 to 45 mg/day FeSO4 (4 to 9 mg/day elemental)
4 to 8 years: 20 to 50 mg/day FeSO4 (4 to 10 mg/day elemental)
9 to 13 years: 30 to 40 mg/day FeSO4 (6 to 8 mg/day elemental)
14 to 18 years: 40 to 75 mg/day FeSO4 (8 to 15 mg/day elemental)
-Give in divided doses (1 to 3 times daily)

or

Tablets (325 mg FeSO4, 65 mg elemental iron)
12 years and older: 1 tablet orally once a day

What other drugs will affect ferrous sulfate?

Take your ferrous sulfate dose 2 to 6 hours before or after taking any of the following:

This list is not complete. Other drugs may interact with ferrous sulfate, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Frequently asked questions

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use ferrous sulfate only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.