Biomarker Glossary

Ferritin

Ferritin is a protein that stores iron in your body. A ferritin blood test is the best single marker of your iron stores and the most reliable way to detect iron deficiency, which is one of the most common nutritional deficiencies in the UK, especially in women.

Also known as: Iron Storage Protein

Ferritin is most informative when read alongside related markers like Iron and Haemoglobin. A single number rarely tells the whole story. If your reading sits outside the typical range, share the full report with your GP or healthcare professional before drawing conclusions.

What is Ferritin?

Ferritin is a protein found mainly inside your cells that stores iron and releases it when the body needs it. The level of ferritin in your blood reflects how much iron is stored across your whole body.

Low ferritin is the earliest sign of iron deficiency. It drops before you become anaemic, which means a ferritin test can catch problems weeks or months before they show up on a standard full blood count (FBC).

Ferritin is also an inflammatory marker. Levels rise during infection, chronic inflammation, liver disease, and some cancers, which is why doctors often interpret ferritin alongside CRP and other iron markers (iron, transferrin, transferrin saturation).

Why test Ferritin?

To investigate symptoms of fatigue, hair loss, restless legs, breathlessness or low mood that might be linked to low iron.
To screen menstruating women, vegetarians, vegans and athletes, who are at higher risk of iron deficiency.
To monitor iron supplementation. Ferritin is the best marker to confirm whether supplements are restoring your iron stores.
To investigate unexplained high iron levels or possible haemochromatosis (genetic iron overload).

To investigate symptoms of fatigue, hair loss, restless legs, breathlessness or low mood that might be linked to low iron.

Ferritin normal range (UK)

Result	What it means
Below 15 ng/mL (women) / 20 ng/mL (men)	Iron deficiency (NHS threshold)
15 to 30 ng/mL	Borderline low, often symptomatic
30 to 200 ng/mL (women)	Adequate
30 to 300 ng/mL (men)	Adequate
Above 300 ng/mL	Elevated, may indicate inflammation, liver disease or iron overload

The NHS uses a low threshold of 15 ng/mL to diagnose deficiency, but many clinicians and researchers consider levels below 50 ng/mL suboptimal, particularly when symptoms are present. Optimal ferritin for an active or menstruating adult is often cited as 50 to 100 ng/mL.

About these ranges. The ranges above are typical UK clinical lab ranges aligned to NHS and Royal College of Pathologists guidance. Your Chxhealth report will show the specific reference range used by our partner lab, Randox, for each marker. Lab ranges vary slightly between providers and assays. Always interpret your results in the context of the range printed on your own report.

What causes high Ferritin?

Inflammation, infection or recent illness (ferritin rises as part of the immune response)
Liver disease (hepatitis, fatty liver, alcohol related liver damage)
Haemochromatosis (genetic iron overload)
Excessive iron supplementation
Frequent blood transfusions
Some cancers (including lymphoma and leukaemia)
Metabolic syndrome and type 2 diabetes
Hyperthyroidism

What causes low Ferritin?

Insufficient dietary iron (vegetarian or vegan diets, low red meat intake)
Heavy menstrual bleeding
Pregnancy (iron demand increases)
Gastrointestinal bleeding (ulcers, polyps, coeliac disease)
Poor iron absorption (coeliac disease, Crohn's disease, gastric surgery)
Endurance exercise (foot strike haemolysis in runners)
Frequent blood donation

Symptoms of high Ferritin

Often no symptoms early on
Joint pain (particularly knuckles)
Fatigue and weakness
Abdominal pain
Loss of libido or erectile dysfunction
Bronze or grey skin tone in severe cases
Liver problems if untreated

Symptoms of low Ferritin

Fatigue, even when sleeping enough
Breathlessness during exercise or stairs
Hair shedding or thinning
Brittle or spoon shaped nails
Restless legs
Pale skin
Frequent headaches
Difficulty concentrating ("brain fog")
Pica (cravings for ice, dirt or paper)

How is Ferritin tested?

Ferritin is measured from a small blood sample, taken by finger prick at home or via a clinic blood draw.

Fasting is not required, but ideally test before any iron supplement or iron rich meal that day.

Because ferritin rises with inflammation, your result is most accurate when you are not unwell. If you have a recent infection or injury, wait 2 to 4 weeks before testing.

Chxhealth samples are analysed by Randox, a UK laboratory accredited by UKAS. Results return in 3 to 5 working days.

How to support healthy Ferritin levels

Eat iron rich foods regularly: red meat, liver, oily fish, eggs, lentils, beans, tofu, dark leafy greens, fortified cereals.
Pair plant iron sources with vitamin C (peppers, citrus, kiwi, broccoli) to improve absorption.
Avoid tea, coffee and calcium rich foods within an hour of iron rich meals, as they inhibit absorption.
If you supplement iron, take it on an empty stomach with vitamin C. Every other day dosing (rather than daily) has been shown to improve absorption in some studies.
If menstrual blood loss is heavy, speak to a healthcare professional. Treating the underlying cause is more effective than chronic supplementation.

These are general lifestyle suggestions. Chxhealth is an information service. For personal medical advice, please speak to a healthcare professional.

Chxhealth panels that test Ferritin

24 Chxhealth biomarker panels include Ferritin. Each is analysed by Randox, a UK laboratory accredited by UKAS. Reports are delivered in 3 to 5 working days.

Ferritin FAQs

What is a good ferritin level?

Above 30 ng/mL is the NHS threshold for adequate iron stores. Many clinicians consider 50 to 100 ng/mL optimal, particularly for menstruating women, athletes or people with persistent fatigue or hair loss.

Can ferritin be normal but iron still low?

Yes. Ferritin rises during infection and inflammation, which can mask underlying iron deficiency. If your ferritin is in the normal range but you have symptoms, check CRP at the same time and consider testing iron, transferrin and transferrin saturation together.

How quickly can ferritin be raised with supplements?

Most people see ferritin rise by 30 to 50 ng/mL over 3 months of consistent iron supplementation. Severe deficiency may need an intravenous iron infusion under medical supervision.

Is high ferritin always serious?

Not always. A modest rise (300 to 500 ng/mL) is often due to inflammation or fatty liver and resolves with treatment. Persistently very high levels (above 1000 ng/mL) need investigation for haemochromatosis, liver disease or other causes.

Should I test ferritin or a full iron panel?

If you only test one marker, ferritin is the best single indicator of iron stores. A full iron panel (ferritin, iron, transferrin, transferrin saturation, TIBC) gives a more complete picture and is recommended when ferritin is borderline or you suspect inflammation.

Often tested with Ferritin

The biomarkers below are commonly investigated alongside Ferritin because they reveal connected aspects of the same physiological picture:

Iron: Together they describe both iron stores and circulating iron.
Haemoglobin: Full picture of iron status moving from stores to red cells.
Vitamin B12: Other classic deficiency causing anaemia and fatigue.
CRP: Inflammation falsely raises ferritin, so CRP helps interpret it.

Choose the right test for your goal

If you are reading about Ferritin because of a specific health goal, our buying guides walk you through which Chxhealth panels fit:

Sources and further reading

This page is informed by guidance from the NHS, NICE, Royal College of Pathologists and other UK authoritative bodies. For deeper detail or to verify the information, see:

About this page. Last reviewed: 13 May 2026. Next scheduled review: May 2027. This page has not yet been independently reviewed by a clinician. It is written from authoritative UK medical guidance (NHS, NICE, Royal College of Pathologists, peer-reviewed sources) but has not undergone formal clinical sign off.

Important. Chxhealth is a UK information service. We do not diagnose, treat or prescribe. The reference ranges and information on this page are general educational content and should not be used as a substitute for advice from a qualified healthcare professional. For any concerns about your health or results, please speak to your GP or another healthcare professional.