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Nutrients

Ferritin

Also known as: Serum ferritin, Ferritin blood test, Ferritin iron storage protein test

Ferritin is a protein complex that safely stores iron inside cells and releases it when the body is in need. Most ferritin concentrations are in the liver, spleen, bone marrow, and muscles, but a small amount circulates in the blood. Measuring serum ferritin provides an indirect estimate of your body’s total iron reserves.

A ferritin test can help identify whether you have a potential iron deficiency or overload. Ferritin levels may also rise in response to inflammation, infection, or obesity—even when iron stores are normal.

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Key takeaways

  • Sample required: Blood

  • Tests for: Ferritin, the body’s primary iron storage protein, to help evaluate iron stores.

  • Healthy range: Typical adult female reference ranges vary by lab (often 24–307 ng/mL). Low ferritin suggests iron deficiency.

What can a ferritin test tell you?

A ferritin test may provide insight into:

  • Iron deficiency. Low ferritin is often the earliest and most reliable marker of iron deficiency anemia—labs can capture it even before hemoglobin drops.

  • Iron overload. Very high ferritin may signal hereditary hemochromatosis — a disease marked by iron buildup — or iron overload from repeated transfusions. Inflammation or chronic disease. Elevated ferritin can occur with infection, cancer, autoimmune conditions, or liver disease.

Because multiple conditions can influence ferritin levels, providers often interpret results alongside other iron studies (serum iron, transferrin saturation, total iron-binding capacity) and clinical context. 

What is being tested?

Ferritin acts as the body’s iron warehouse. Each ferritin molecule can store thousands of iron atoms in a safe, soluble form. This prevents free iron from causing cellular damage and ensures iron is available for key processes like:

  • Making hemoglobin in red blood cells

  • Supporting muscle metabolism (myoglobin)

  • Enabling enzyme reactions that are essential for growth and energy

Abnormal ferritin levels signal a disruption in how your body manages iron balance. Ferritin correlates positively with body iron stores and can rise independently due to inflammation.

Where is the ferritin test typically included?

Ferritin is not part of routine blood panels. It is usually ordered:

  • Alongside iron studies when anemia or iron overload is suspected

  • As part of monitoring iron supplementation or treatment for anemia

  • As part of a broader workup to help evaluate unexplained fatigue, weakness, or chronic disease

Who should get a ferritin test?

Your provider may recommend a ferritin test if you:

  • Have symptoms of anemia (fatigue, weakness, pale skin, shortness of breath)

  • Show signs of iron overload (joint pain, skin bronzing, liver enlargement)

  • Have chronic conditions linked to inflammation or iron imbalance

  • Are being monitored for iron therapy effectiveness

  • Have a family history of hemochromatosis or other iron-related disorders

How Labs by Hers works

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    Book your test

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  • 2

    Get your results

    Review your lab results to understand which areas of your health may need attention.

  • 3

    Spot early signals

    Identify potential health risks or system imbalances before they become more serious.

  • 4

    Get your action plan

    Receive expert guidance tailored to your health profile and test results.

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    Improve over time

    Track your progress through a mid-year panel and ongoing provider check-ins.

Not available in all 50 states. Eligibility and provider order required. Lab results alone are not intended to diagnose, treat, or cure any condition. A provider will reach out about critical results and plans include access to 24/7 provider messaging.

Images for illustrative purposes only.

Frequently asked questions

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What causes changes in ferritin levels?

Increased ferritin causes include hemochromatosis, repeated blood transfusions, chronic liver disease, inflammatory conditions, metabolic syndrome, and obesity. Low ferritin levels often result from iron deficiency due to chronic blood loss, low dietary iron intake, malabsorption (e.g., celiac disease, bariatric surgery), or long-term use of acid-reducing medications.

Can this test be done at home?

Yes. Some at-home test kits include ferritin, though accuracy depends on lab analysis.

Is fasting required?

Not usually. But if your provider orders a full iron panel, fasting may be requested.

How long do results take?

Results will vary based on the lab, but typically 1–2 business days.

How often should I get tested?

There is no universal testing schedule. Ferritin is typically tested if you’re being treated for iron deficiency, monitored for iron overload, or if symptoms change.

What tests are related to this biomarker?

• Serum iron

• Total iron-binding capacity (TIBC)

• Transferrin saturation (TSAT)

• Hemoglobin and hematocrit

• Liver function tests

The information provided here is for informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always talk to a qualified healthcare provider about your specific health concerns.

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Ferritin/CRP ratio

This ratio compares ferritin, your iron storage protein, with C-reactive protein (CRP), a marker of inflammation. A normal ratio means there is a healthy balance between your iron stores and inflammation.

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Folate, RBC

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Iron

Iron helps make hemoglobin, which carries oxygen in the blood. Normal levels of iron support daily energy and focus.

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Iron Binding Capacity

This marker measures how well proteins in your blood (like transferrin) can carry iron. Normal levels mean your body is transporting iron effectively.

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Iron % Saturation

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Zinc

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Carbon Dioxide

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Calcium

Calcium supports strong bones, teeth, and steady muscle contractions. Calcium also plays a key role in heart rhythm and nerve signaling.

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Chloride

Chloride helps your body maintain fluid balance, stomach acid production, and the right acidity (pH) for enzyme function (chemical reactions in the body).

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Potassium

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Reviewed by Felix Gussone, MD

Published 12/04/2025