Transferrin

Also known as: Siderophilin

The protein that transports iron through the blood — the vehicle rather than the cargo.

Rounds out the iron picture: transferrin rises when iron is scarce (the body making more carriers) and falls in inflammation, malnutrition and liver disease.

🔒 The full Transferrin protocol is inside the Academy

Optimal ranges, root causes, and the complete correction protocol — nutrition, supplements, lifestyle, hormones and peptides — plus 100+ other markers.

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📚 Standard clinical chemistry reference; WHO iron status assessment guidance.

🩸 Test your Transferrin

Order directly through Marek Diagnostics — no doctor's visit needed, drawn at any Quest location in the US. Code CAMERON applies 10% off automatically.

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What Transferrin is usually tested alongside

On its own, one marker is a data point. These panels include Transferrin plus the markers that make it interpretable — each names every test, why it is on the list, and loads the whole set into your cart in one click at 10% off.

🔋 Chronic Fatigue Workup $211.50
includes this + 11 more markers — Persistently exhausted despite adequate sleep, and either haven't been tested or were told everything is normal.
🌱 Male Starter $108.00
includes this + 6 more markers · built for men — Never had proper bloodwork, or want the highest-value snapshot for the least money.
🩸 Iron Deficiency Without Anemia $88.20
includes this + 6 more markers · built for women — Exhausted, breathless on stairs, hair shedding, brittle nails, restless legs, brain fog — and you've been told your blood count is normal. Extremely common in menstruating women, endurance athletes, and anyone plant-based.
🌱 Female Starter $66.60
includes this + 6 more markers · built for women — Never had proper bloodwork, or want the highest-value snapshot for the least money.

Why your Transferrin might be wrong

Most abnormal results are interference, not disease. These are the things that measurably move this specific marker — check them before you change anything. Each one says whether the number is wrong and should be repeated, badly timed and should be redrawn, or real with a cause worth explaining.

💊 Oestrogen — the pill, HRT, pregnancyA real change — account for the cause

Raises transferrin independently of iron status, which lowers the calculated saturation and can imply deficiency that is not there.

Interpret saturation alongside ferritin rather than alone.

🏃 Inflammation and liver diseaseA real change — retest once it passes

Transferrin is a negative acute-phase reactant — it falls with inflammation, the opposite direction to ferritin.

Read the whole iron panel together; the two moving opposite ways is itself informative.

💊 Iron supplements

Falsely elevates serum iron for hours after a dose.

Hold iron supplements 24 hours before an iron panel.

What Transferrin means in combination

A single marker tells you a little. Combinations tell you the story — these are the named patterns this marker takes part in, and what each one points at.

Iron deficient without being anaemic
Ferritin low · Iron saturation <20% · Transferrin high · Haemoglobin still normal

Stores empty long before haemoglobin falls, so a normal CBC is routinely used to tell people their iron is fine. The fatigue, hair shedding, breathlessness and restless legs arrive in this phase, not the anaemic one.

Find the cause, do not just supplement — heavy periods, gut blood loss, coeliac, over-donation. Unexplained iron deficiency in a man or a postmenopausal woman warrants gastrointestinal evaluation. Iron bisglycinate, alternate-day, with vitamin C.

What to test next

Markers rarely answer alone. These are the ones that put Transferrin in context — each with its own full breakdown.

Frequently asked questions

What is a normal Transferrin level?

215–365 mg/dL Ranges vary by laboratory and assay — always compare to the range printed on your own report.

What is the optimal Transferrin level?

Optimal ranges, root causes and the full correction protocol are available inside Coach Cam's Peptide Academy.

What causes high Transferrin?

See the full breakdown inside the Academy.

What causes low Transferrin?

See the full breakdown inside the Academy.

How do I test Transferrin?

You can order Transferrin directly through Marek Diagnostics without a doctor's visit — drawn at any Quest Diagnostics location in the US. Code CAMERON applies 10% off automatically.

Important: This page is education only. The ranges shown are published reference and functional ranges from the cited literature — not a diagnosis and not medical advice. Lab ranges vary by assay and laboratory; always compare against the range printed on your own report and discuss your results with a qualified healthcare provider.