Ferritin
The main iron-storage protein; blood levels reflect the body's iron reserves.
| Typical reference range (male) | 30–400 ng/mL |
| Typical reference range (female) | 15–150 ng/mL |
Ranges vary by laboratory, method, age and sex: always use the range printed on your own report. Why labs differ.
What it measures
Ferritin stores iron inside cells, mainly in the liver, spleen and bone marrow. A small amount circulates in proportion to total iron stores, making serum ferritin the best single test for iron status.
Why it matters
Low ferritin is the earliest and most specific sign of iron deficiency, appearing before anemia. Because ferritin is also an acute-phase protein, high values may reflect inflammation rather than excess iron.
What a high result can mean
High ferritin can result from inflammation or infection, fatty liver, alcohol use, metabolic syndrome, liver disease, some cancers and iron overload (hereditary hemochromatosis, frequent transfusions). Transferrin saturation helps distinguish true iron overload.
What a low result can mean
Low ferritin indicates depleted iron stores, commonly due to menstruation, pregnancy, blood donation, low dietary iron (e.g. vegetarian diets), GI blood loss, celiac disease or heavy endurance training. Many clinicians consider values below 30 ng/mL to indicate iron deficiency, and symptoms like fatigue or hair shedding can occur below 30-50.
What affects the result
Inflammation, infection or intense exercise can temporarily raise ferritin and mask deficiency; check hs-CRP. Iron supplements raise it over weeks to months. Interpret with iron, TIBC, transferrin saturation and the CBC.
Units and conversion
Usually reported in ng/mL.
- From ug/L: multiply by 1 to get ng/mL
- From pmol/L: multiply by 0.445 to get ng/mL
Also called on lab reports
Ferritin, Serum, Serum Ferritin
Related tests: Iron Status
This page is educational and does not replace advice from a healthcare professional.