Iron and haematology . Patient guide

TIBC and Transferrin Saturation (TIBC, TSAT)

Also known as: Total iron binding capacity, Iron binding capacity

What is TIBC, TSAT

Total iron binding capacity (TIBC) measures the total amount of iron the bloodstream can carry on its transport protein transferrin. Transferrin saturation is the percentage of those carrying sites currently occupied. Together they distinguish iron deficiency from iron overload and from anaemia of chronic disease in a way that ferritin alone cannot.

This biomarker entry is being clinically reviewed by our team. The factual content draws on UK guidance (NICE, NHS, Royal Colleges and the relevant speciality society where cited).

Reference range

Reported in µmol/L (TIBC), % (transferrin saturation). Final reports always carry the issuing laboratory's range, which is what your clinician will interpret against.

Group Range Note
TIBC adult range 45 to 72 µmol/L
Transferrin saturation typical 20 to 50 %
Transferrin saturation suggesting iron deficiency under 20 %
Transferrin saturation suggesting iron overload over 50 % (over 45% in women)

What it is

Transferrin is the iron transport protein. Each molecule can bind two iron atoms. TIBC reflects how many transferrin binding sites are present, and transferrin saturation is the percentage actually occupied (calculated as serum iron divided by TIBC). In iron deficiency the body upregulates transferrin to scavenge more iron, so TIBC rises and saturation falls. In iron overload the opposite happens.

Why a clinician would order it

TIBC and transferrin saturation are requested as part of standard UK iron studies whenever a comprehensive picture of iron status is needed: in unexplained fatigue, hair shedding, anaemia, pre-operative work-up (especially before hair transplant), or in suspected haemochromatosis (genetic iron overload).

If your level is outside the range

Symptoms of low TIBC, TSAT

  • Low TIBC: usually no specific symptoms, often part of anaemia of chronic disease picture
  • Low transferrin saturation: same symptoms as iron deficiency (fatigue, hair shedding, brittle nails, breathlessness)

What low can indicate. Low TIBC: chronic disease, malnutrition, inflammation, nephrotic syndrome. Low transferrin saturation: iron deficiency.

Symptoms of high TIBC, TSAT

  • High TIBC: typical of iron deficiency state
  • High transferrin saturation: suggests iron overload - joint pain, fatigue, skin pigmentation change, abdominal discomfort, eventually diabetes and liver dysfunction in haemochromatosis

What high can indicate. High TIBC: iron deficiency. High transferrin saturation: hereditary haemochromatosis, repeated transfusions, or iron supplementation in someone who already has adequate stores.

Testing tips

Morning fasting blood draw is preferred for the full iron studies panel. Avoid iron supplements for 24 hours before testing. A transferrin saturation above 45 percent in women or 50 percent in men, particularly with a raised ferritin, warrants genetic testing for haemochromatosis (HFE gene mutations).

Where you can get this tested

TIBC and Transferrin Saturation is included in the following WMG Health panels. Same-day appointments at our Harley Street clinic, with results clinician-reviewed.

General Wellness
£279
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Want a specific combination of markers we do not have a panel for? Build a custom panel and our clinicians will design one for you.

Symptoms often investigated with TIBC and Transferrin Saturation

TIBC and Transferrin Saturation is commonly tested when patients present with the following symptoms. If any of these resonate with you, the linked guides explain what to look for and which test pathway is appropriate.

Stress-Related Hair Loss: Testing the Real Drivers Severe stress can trigger heavy shedding 2 to 4 months later. Testing identifies the nutritional and thyroi... Read symptom guide → Hair Loss After COVID-19 or a Viral Illness Heavy shedding 2 to 4 months after COVID-19 is well documented (a viral telogen effluvium). A targeted pane... Read symptom guide → Erectile Changes: Blood Work That Matters Erectile changes can be vascular, hormonal or medication-related. A blood panel rules out the metabolic and... Read symptom guide → Perimenopause: Symptoms and When to Test Hot flushes, irregular cycles, sleep disruption and mood change can begin years before menopause. FSH, oest... Read symptom guide → Menopause: Symptoms and Bloodwork Context Menopause is diagnosed clinically (12 months without a period). Bloodwork has a role in younger women (unde... Read symptom guide → Thyroid Symptoms: When and What to Test Fatigue, weight change, hair loss, cold intolerance and mood change can all be thyroid driven. A full TSH, ... Read symptom guide →

Read this marker alongside another

TIBC and Transferrin Saturation is most useful when interpreted together with the markers below. Each guide walks through the 4-quadrant matrix our clinicians use when both come back at once.

Iron studies pair Ferritin and TIBC (total iron binding capacity) Ferritin and TIBC are interpreted together because ferritin can be misleadingly normal or even raised during inflammation, while TIBC moves in the opposite direction during true iron deficiency. Read the interpretation guide →

Related markers

Ferritin Iron and haematology Serum Iron Iron and haematology

Sources

UK guidance our clinicians use when interpreting this marker.

This page is general patient information, not personal medical advice. A GMC-registered clinician will review your results and tailor any interpretation to you. See our Editorial Policy for how we write and review content.

Common questions about TIBC, TSAT

What is a normal TIBC, TSAT range?

TIBC adult range: 45 to 72 (µmol/L). Transferrin saturation typical: 20 to 50 (%). Transferrin saturation suggesting iron deficiency: under 20 (%). Transferrin saturation suggesting iron overload: over 50 (% (over 45% in women)). Always interpret your own results against the laboratory range printed on your report, since assay-specific reference ranges vary.

What does a low TIBC, TSAT result mean?

Low TIBC: chronic disease, malnutrition, inflammation, nephrotic syndrome. Low transferrin saturation: iron deficiency.

What does a high TIBC, TSAT result mean?

High TIBC: iron deficiency. High transferrin saturation: hereditary haemochromatosis, repeated transfusions, or iron supplementation in someone who already has adequate stores.

Do I need to fast or prepare for the TIBC, TSAT blood test?

Morning fasting blood draw is preferred for the full iron studies panel. Avoid iron supplements for 24 hours before testing. A transferrin saturation above 45 percent in women or 50 percent in men, particularly with a raised ferritin, warrants genetic testing for haemochromatosis (HFE gene mutations).

Can I order a TIBC, TSAT blood test privately in London?

Yes. WMG Health offers TIBC, TSAT as part of bespoke panels and several pre-built panels at our 134 Harley Street clinic. Results are clinician-reviewed by a GMC-registered doctor within 4 hours for the most common assays. Bespoke panels from £180; bookings via /contact/ or 020 3239 3378.