ferrous sulfate
Iron is a mineral supplement that's taken by children and adults to prevent or treat low iron levels. Sometimes, a provider might only recommend iron supplements for a period of time, like during pregnancy. Iron supplements come in many forms, such as ferrous sulfate and ferrous gluconate, that differ in how much iron they contain and dosing. Iron supplements are also available in various formulations, such as gummies, slow-release tablets, or liquid solutions. Some side effects of iron supplements include constipation and nausea.
What is Iron supplements?
What is Iron supplements used for?
Low iron levels
How Iron supplements works
Iron is a supplement. Your body needs iron to make healthy red blood cells, which are needed to carry oxygen to all parts of the body. Iron also helps your body make a protein that gives oxygen to your muscles. Iron supplements raise the level of iron in the body when you don't have enough.
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What are the side effects of Iron supplements?
Common Side Effects
- Constipation
- Diarrhea
- Nausea
- Vomiting
- Dark stools
- Stomach pain
Source: DailyMed
The following side effects have also been reported
Side effects that you should report to your care team as soon as possible:
- Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome):
- Constipation
- Dark stools
- Metallic taste in mouth
- Nausea
- Upset stomach
Pros and cons of Iron supplements
Pros
Taken by mouth
Available in tablets, capsules, gummies, and liquid forms
Some forms taken just once daily (e.g., ferrous sulfate)
Cons
Can cause constipation and nausea
Can interact with certain medications and cause them to not work as well
Milk products can cause your body to not absorb iron as well
Pharmacist tips for Iron supplements
It's best to take iron supplements on an empty stomach because your body absorbs iron best on an empty stomach.
If you experience stomach pain or nausea from taking iron supplements on an empty stomach, you can try taking it with food to ease those side effects. If you take iron with food, it's best to take it with a glass of orange juice or a vitamin C supplement because these can help your body better absorb the iron.
Taking iron supplements can cause your stool to look black or darker in color. This is expected and won't cause any harm. But let your provider know right away if you also notice blood in the stool because you might need more medical attention.
Don't crush or chew the controlled-release or extended-release formulations of iron supplements. They're made with a special coating that releases the medication slowly and steadily over time. Crushing or chewing these pills can cause too much iron to be released at once. This might worsen side effects, like constipation and nausea.
Let your provider know if you're taking other medications before starting iron supplements so they can help you determine if there are any interactions between your medications. For example, you need to separate iron supplements from levothyroxine. Iron prevents your body from absorbing levothyroxine, so taking this combination together means that levothyroxine might not work as well to treat your thyroid condition.
If you're taking any other multivitamins, double check the list of ingredients in your vitamins to see if has iron. If so, you might not need any additional iron supplements. Taking too much iron can raise your risk for side effects, like constipation or stomach upset. And in rare, but serious cases, you might experience iron toxicity.
Speak to your provider before starting iron supplements if you're pregnant, planning to become pregnant, or breastfeeding. Your provider can let you know how much iron to take based on your body's needs. In some cases, you might already be taking iron through other supplement products, such as prenatal vitamins, so you might not need additional iron supplements.
Frequently asked questions about Iron supplements
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What are the risks and warnings for Iron supplements?
Iron supplements can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Risk of accidental overdose
Keep iron supplements away and out of reach of children to prevent them from accidentally taking it. Accidental overdose with medications containing iron is a leading cause of fatal (deadly) poisoning in children under 6 years old. Symptoms of iron overdose include severe stomach pain, vomiting, and diarrhea. If you suspect that you or your child has accidentally overdosed on iron supplements, get emergency medical help or contact the poison control center at 1-800-222-1222 right away.
Iron supplements dosage forms
Typical dosing for Iron supplements
Each iron supplement formulation can contain different strengths or even combinations of different forms of iron. Carefully read the package label of your iron product for specific instructions.
Some examples include:
Ferrous sulfate (325 mg tablet): For adults and children over 12 years of age, take 1 tablet by mouth daily, preferably with a meal, or as directed by your provider. Speak to your child's provider to get an appropriate dose for your child under 12 years old.
Ferrous gluconate (324 mg tablet): For adults, take 1 tablet by mouth three to four times daily. Speak to your child's provider to get an appropriate dose for your child.
Ferrous fumarate (325 mg tablet): For adults, take 1 tablet by mouth daily, or as directed by your provider.
Polysaccharide-iron (326 mg capsule): For adults, take 1 to 2 capsules by mouth daily, or as directed by your provider.
How much does Iron supplements cost?
Iron supplements contraindications
Hemochromatosis (too much iron builds up in the body)
Hemosiderosis (too much iron depositing in the tissues or organs)
What are alternatives to Iron supplements?
Iron deficiency (including iron-deficiency anemia) in people who either have already tried or can't take oral iron supplements
What is the latest news about Iron supplements?
Iron supplements images
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References
Best studies we foundAkron Pharma. (2023). Fe-Vite iron oral solution- ferrous sulfate solution [package insert]. DailyMed.
Alleyne, M., et al. (2008). Individualized treatment for iron-deficiency anemia in adults. The American Journal of Medicine.
Hamilton, J. P. A. (2022). Hemosiderosis. Merck Manual Consumer Version.
LiverTox: Clinical and Research Information on Drug-Induced Liver Injury. (2012). Concentrations of elemental iron in typical iron tablets. National Institute of Diabetes and Digestive and Kidney Diseases.
National Institutes of Health, Office of Dietary Supplements. (2023). Iron: Fact sheet for consumers.
Nnodum Pharmaceuticals. (2023). Iferex 150- polysaccharide-iron complex capsule [package insert]. DailyMed.
Paddock Laboratories, LLC. (2017). Ferrous gluconate tablet [package insert]. DailyMed.
Pharbest Pharmaceuticals, Inc. (2021). Ferrous sulfate- ferrous sulfate 325 mg red tablet, film coated [package insert]. DailyMed.
Pharmics, Inc. (2015). Ferretts- ferrous fumarate tablet, film coated [package insert]. DailyMed.
Rockey, D. C., et al. (2006). Treatment of iron deficiency. Gastroenterology.
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