Transferrin saturation, sometimes written as trans sat or TRF sat, shows what percentage of your iron-carrying protein is loaded with iron. A low percentage means there isn't much iron on the move, which often goes with low ferritin and iron deficiency. A high percentage can mean iron is building up, and if it stays high on repeat tests, it's worth checking for haemochromatosis, an inherited condition that's common in people with northern European roots. The lab range is 20 to 45%, and we aim for 24 to 40%. It's part of the iron studies in your Vively Baseline Health Check.
Check Transferrin Saturation alongside 70+ other markers in Vively's Baseline Health Check.
Every marker in range? Get your $99 back. T&Cs apply.Want to save 25%? Try our 4-Month Reset insteadTransferrin Saturation is the percentage of transferrin that is bound to iron. It shows how effectively iron is being transported through the bloodstream, measured as a percentage (%) in Australia.
Dr Michelle Woolhouse, Vively Medical Director, explains what transferrin saturation measures, what a low or high result can suggest, and why to read it with your full iron studies, ferritin and haemoglobin. The common lab range for transferrin saturation is 20 to 45%. Vively's optimal range is tighter, at 24 to 40%.
General information, not medical advice. Talk to your doctor about your own results.
Iron availability influences how efficiently your body produces energy, supports metabolic function, and maintains day-to-day performance. Transferrin Saturation helps you understand whether your iron delivery system is functioning in a way that supports long-term vitality.
These ranges help place your result in context and guide proactive lifestyle choices.
Nutrition patterns, iron intake from food, absorption efficiency, digestive health, and overall metabolic demand can all influence this result. Hydration, timing of meals, and general wellbeing may also contribute to shifts.
A result outside the optimal range signals that your current iron availability may not fully support your energy needs or day-to-day metabolic performance. It’s an early prompt to review factors such as diet, absorption, and overall nutrient balance.
A nutrition pattern that includes iron-rich whole foods, vitamin C for absorption, balanced protein intake, and habits that support gut function can all help maintain healthier levels. Regular tracking offers insight into how your choices shape your long-term metabolic health.
This information is provided for general health and wellness purposes only and does not replace medical advice.
A transferrin saturation blood test shows how much of the iron-transport protein transferrin is actively carrying iron. It helps clarify how available iron is for energy production and red blood cell support at the time of testing, rather than total stored iron alone.
Low saturation transferrin results suggest that only a small proportion of transferrin is carrying iron. This can indicate reduced iron availability for daily metabolic needs and may prompt a closer look at dietary intake, absorption, or overall nutrient balance.
High iron transferrin saturation means a larger percentage of transferrin is bound to iron. In context, this can reflect increased iron intake or altered regulation of iron transport, and it is best interpreted alongside other iron markers to understand the full picture.
Among 2,312 Vively members tested in 2024 to 2026, women aged 40 to 49 had a median transferrin saturation of 29% (middle half 21 to 36). Men the same age: 30%. The lab range is 20 to 45%. A member median is not a target.
The line is the median member at each age. The shaded bands show where most members sit. The dashed red lines are the lab range.
| Group (%) | Members | Median | Middle 50% | 5th to 95th percentile | Lab range |
|---|---|---|---|---|---|
| Women 18 to 29 | 130 | 28 | 22 to 39 | 11 to 52 | 20 to 45 |
| Women 30 to 39 | 407 | 28 | 20 to 36 | 12 to 49 | 20 to 45 |
| Women 40 to 49 | 464 | 29 | 21 to 36 | 13 to 51 | 20 to 45 |
| Women 50 to 59 | 307 | 28 | 21 to 34 | 14 to 47 | 20 to 45 |
| Women 60 and over | 143 | 26 | 21 to 33 | 15 to 48 | 20 to 45 |
| Men 18 to 29 | 122 | 30 | 25 to 38 | 16 to 58 | 20 to 45 |
| Men 30 to 39 | 276 | 31 | 24 to 40 | 17 to 51 | 20 to 45 |
| Men 40 to 49 | 269 | 30 | 24 to 38 | 18 to 49 | 20 to 45 |
| Men 50 to 59 | 124 | 30 | 24 to 37 | 16 to 49 | 20 to 45 |
| Men 60 and over | 70 | 27 | 21 to 35 | 15 to 46 | 20 to 45 |
Pick your sex and age, then type your result.
What is a normal transferrin saturation for my age?
Among 2,312 Vively members (first blood test, January 2024 to October 2026), the median transferrin saturation for women was 28% at 18 to 29, 28 at 30 to 39, 29 at 40 to 49, 28 at 50 to 59 and 26 at 60 and over. For men it was 30% at 18 to 29, 31 at 30 to 39, 30 at 40 to 49, 30 at 50 to 59 and 27 at 60 and over.
The lab range is 20 to 45%. A member median is not a target or a diagnosis. If your result is outside the range on your report, talk to your GP.
How to get it: Included in the Baseline Health Check. A GP from our network signs your request after a short telehealth consult, so you don't need to visit your own GP first. See how a blood test without a referral works.
Related tests: Transferrin, Ferritin, Transferrin Iron Binding Capacity (TIBC), Iron
The Baseline Health Check reads 70+ markers, then your dietitian turns your results into a plan. $99 a month, first test included.
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