Evidence-Based Clinical Library · Organ

Transferrin saturation: what your result means.

Updated 07 August 2026 · HodieLabs Clinical Governance Lead · The HodieLabs Evidence-Based Clinical Library

Percentage of transferrin carrying iron; shows iron delivery to tissues. Transferrin saturation is measured by blood test as part of the Organ panel in the HodieLabs Health Blueprint.

Why Transferrin saturation matters

TSAT = serum iron ÷ TIBC × 100; reflects the proportion of transferrin actively carrying iron. Morning fasting sample is essential. TSAT fluctuates significantly with meals and time of day.

Associated risks when out of range: Iron deficiency (low). Iron overload risk (high).

What the clinical evidence shows

The evidence base behind how the HodieLabs Evidence-Based Clinical Library interprets Transferrin saturation, from randomised trials, prospective cohorts and genetic (Mendelian randomisation) studies. Full citations in the reference list below.

  • Busselton haemochromatosis study (Olynyk et al. NEJM 1999): persistently elevated transferrin saturation was the key screening signal for HFE haemochromatosis in Australian population screening, a treatable condition affecting ~1 in 190 of northern-European ancestry.

Evidence-based reference ranges

The HodieLabs Evidence-Based Clinical Library interprets Transferrin saturation against published clinical authority standards, never arbitrary "optimal" ranges. Measured in %:

BandRange (%)
Optimal15–50 %
Low<15 %
High>50 %
Very high>70 %
Reference standard: RCPA Australian pathology reference intervals; transferrin saturation 15–50% normal. <15% suggests iron deficiency, >50% iron overload screen.

Clinical interpretation

  • TSAT = serum iron ÷ TIBC × 100; reflects the proportion of transferrin actively carrying iron.
  • Morning fasting sample is essential. TSAT fluctuates significantly with meals and time of day.
  • TSAT > 45% on two occasions is the screening threshold for hereditary haemochromatosis.

What improves it: the evidence-based levers

  • TSAT < 20% with low ferritin confirms iron deficiency. Consider supplementation
  • TSAT > 45% warrants investigation for haemochromatosis (HFE gene testing)

Recommended testing frequency: Annual, as part of a comprehensive panel. Single markers are always interpreted in context.

How Transferrin saturation testing works at HodieLabs

Transferrin saturation is measured in every Health Blueprint at our Melbourne Preventative Health & Longevity Clinic, interpreted by a doctor against the guideline-cited ranges above and tracked over time through your HodieLabs membership.

References

1. Olynyk JK, et al. A population-based study of the clinical expression of the hemochromatosis gene. N Engl J Med. 1999;341:718–724.

This page is general information from the HodieLabs Evidence-Based Clinical Library, not medical advice. Speak with your GP about what testing and care is appropriate for you.

Frequently asked questions

Percentage of transferrin carrying iron; shows iron delivery to tissues.

The HodieLabs Evidence-Based Clinical Library optimal range is 15–50 %, based on RCPA Australian pathology reference intervals; transferrin saturation 15–50% normal. <15% suggests iron deficiency, >50% iron overload screen.

Annual testing is recommended for most adults as part of a comprehensive preventative panel; more often if a result is being actively managed.

Evidence-supported levers include: tsat < 20% with low ferritin confirms iron deficiency. Consider supplementation, tsat > 45% warrants investigation for haemochromatosis (hfe gene testing). Interpretation and an action plan should always involve your doctor.

Transferrin saturation is measured in the HodieLabs Health Blueprint at our Melbourne Preventative Health and Longevity Clinic at 85 Spring Street, with doctor-led interpretation against evidence-based reference ranges.

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Transferrin saturation and 50+ biomarkers, measured and doctor-interpreted at our Melbourne clinic.

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