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Transferrin is a protein that carries iron around your body. A result from the iron tests that is too low or too high can point to anaemia or to too much iron in your body.[1]
On this page, you can read what transferrin is, what the guidelines say about a level that is too low or too high, what affects your level and which values are best to look at alongside it.
Also known as: transferrin test, serum transferrin. At the lab: TRAF.
Transferrin is a protein that carries iron around your body. The transferrin test measures this protein in your blood.[1]
Iron is a mineral your body needs for growth and development. Your body uses iron to make hemoglobin. That is a protein in your red blood cells that carries oxygen from your lungs to the rest of your body.[1]
Iron is also important for healthy muscles, your bone marrow and the way your organs work. Your body also needs iron to make some hormones.[1]
Some people find it harder to get enough iron. For example, if you have heavy periods, are pregnant or breastfeed your baby, give blood often, or have a malignant condition, certain digestive conditions or a heart condition. Babies also find it harder, especially if they were born early or with a low birth weight. Most people in the United States do get enough iron.[1]
Too little iron in your body is the most common cause of anaemia. With anaemia, your blood has fewer red blood cells than normal.[1]
With too little iron, you may feel weak or tired, feel dizzy, be short of breath or have a heartbeat with an unusual pace or rhythm. Low iron sometimes only causes symptoms once it is very low. That is why your healthcare provider may also order an iron test when you have no symptoms.[1]
With too much iron, you may feel weak or tired, have pain in your joints, especially in your knees or hands, have stomach pain, have less interest in sex or have trouble getting an erection. Your skin can also turn grey, metallic or bronze in colour.[1]
Labplusarts, the lab BioProfile works with, uses a reference range of 2.2 to 3.6 g/l for transferrin. The lab calls a level between those limits normal.[2]
| Value | What it can mean | Who it is for |
|---|---|---|
| 2.2 to 3.6 g/l[2] | The lab calls this normal | The lab does not name a separate group |
Source: Labplusarts, the lab's reference range for transferrin (TRAF).[2]
MedlinePlus does not give a separate limit for transferrin. The source talks about the iron tests together. If one or more results show that your iron is too low, this can point to anaemia caused by iron deficiency, another type of anaemia or an inherited blood condition. Not everyone with low iron has anaemia.[1]
Here too, the source talks about the iron tests together. If one or more results show that your iron is too high, this can point to too much iron building up in your body, either inherited or caused by another condition, or to a liver condition. An unusual result does not always mean there is something you need care for.[1]
BioProfile is working on its own zones for each value, from risk to optimal. A doctor reviews those zones before they appear in your result.
The iron in your blood changes over the day and can be higher in the morning. The test is usually done in the morning. Your healthcare provider may ask you not to eat or drink for 12 hours beforehand.[1]
Some medicines can affect your iron levels, such as the contraceptive pill and medicines containing oestrogen.[1]
In women, iron levels can be lower during the menstrual cycle.[1]
You get iron from your food or from supplements. Many multivitamins also contain iron. How much iron you need each day depends on your age, your sex and whether you mainly eat plant-based foods.[1]
Transferrin is in all five packages, from BioProfile 31 to BioProfile 150.[3]
The BioProfile editorial team wrote this page on 2 October 2026 from the sources below, which we read on 2 October 2026. Every number on this page appears in one of those sources, with that source's number next to it. An expert has yet to check this page; once checked, the expert's name and the date of the check will appear at the top. This page offers explanation, not a diagnosis. Discuss an abnormal value with your GP.
