Normal Ferritin Levels in the UK: What Counts as Low?

There is no single normal ferritin level in the UK: each NHS laboratory prints its own range, and the lowest result it counts as normal runs from 11 to 30 µg/L. A result that one laboratory reports as normal can therefore be flagged as low by another. Guidelines add a second yardstick: the British Society of Gastroenterology (BSG) describes ferritin under 30 µg/L as generally indicative of low iron stores¹. Ferritin also rises with inflammation, so a result inside the range is read in clinical context rather than on its own³.

Below are the ranges printed by 13 NHS laboratories, the thresholds UK guidelines use, and why a "normal" result can still leave a question open. A later section covers how we handle ferritin results for iron infusion at our Mayfair clinic. This is general information, not advice on your own result: a GP or the clinician who requested the test can interpret it.

What ferritin measures

Ferritin is a blood protein that reflects the iron your body has in store, and UK laboratories report it in micrograms per litre (µg/L). The BSG guideline calls serum ferritin "the single most useful marker" of iron deficiency anaemia¹. Some laboratories and papers write ng/mL instead, which is the same number¹⁷. Ferritin is also an acute-phase protein, so its level can be falsely high during infection or inflammation^{1, 4}.

What NHS laboratories print as the normal range

Across 13 NHS laboratories in England and Scotland, the lowest ferritin counted as normal runs from 11 to 30 µg/L for women and from 12 to 30 µg/L for men. Six of the 13 print a lower limit for women below 15 µg/L (11 to 13), and four start their normal band at 30 µg/L. We opened each laboratory's own test page in October 2026 (they are listed in the sources). We found no published adult range for a laboratory in Wales or Northern Ireland, so neither is represented.

Four examples from across the spread, in µg/L:

Bristol (Severn Pathology): women 11 to 310, men 24 to 340⁴
Cornwall: women 15 to 200, men 15 to 300⁵
Birmingham: women 20 to 235, men 22 to 501⁶
Edinburgh and the Lothians: premenopausal women 30 to 200, men and postmenopausal women 30 to 300⁷

Some laboratories also split women's ranges by age: the University Hospitals of North Midlands prints 15 to 200 for women aged 18 to 54 and 15 to 300 from 55 at Royal Stoke and County, and 12 to 160 and 12 to 240 at Leighton and Macclesfield¹⁰.

The ranges differ because each laboratory sets its own, often starting from the analyser manufacturer's figures^{11, 13} or a locally derived range⁶. A 2024 systematic review reports that the five most-used commercial ferritin assays carry lower limits with a median of 11 µg/L for women and 22 µg/L for men²⁰.

What UK guidelines use as thresholds

UK guidance mostly uses 30 µg/L as the line for low iron stores, and counts stores as absent below 15 µg/L (BSG) or 12 µg/L (NHS Highland). The main cut-offs, from the lowest:

Under 12 µg/L: NHS Highland's guideline reads this as complete absence of stored iron⁹.
Under 15 µg/L: the BSG guideline calls this "indicative of absent iron stores"¹.
Under 30 µg/L: the BSG guideline calls this "generally indicative of low body iron stores"¹. NHS Highland reads it as iron depletion⁹, and NHS Lothian has unified its adult lower limit at 30 µg/L, with a low haemoglobin alongside pointing to iron deficiency anaemia⁸.
30 to 50 µg/L: NHS Highland says this range "can also be consistent with iron deficiency", especially in older patients and where inflammation is present⁹.
Pregnancy: Hywel Dda University Health Board in Wales counts a ferritin under 30 µg/L at any stage of pregnancy as low²¹.

The BSG notes that the lower limit of normal at most laboratories lies between 15 and 30 µg/L¹. Most of the 13 laboratories do print a lower limit in that band, but six print a lower limit for women of 11 to 13 µg/L, which is why the same result can be "normal" at one laboratory and "low" at another.

Why a normal result can still leave the question open

A result inside the laboratory range does not always rule out low iron stores, because inflammation raises ferritin and because the cut-off itself is still debated.

On inflammation, the BSG says "apparently normal levels may occur with iron deficiency in the context of an inflammatory disease process"¹. It adds that a ferritin above 150 µg/L is unlikely with absolute iron deficiency, even with inflammation¹. A Bath laboratory guide for GPs (non-pregnant adults) suggests 11 to 100 µg/L in women and 24 to 100 µg/L in men as the range where inflammation, infection and other conditions that raise ferritin should be excluded³.

On the cut-off, some researchers argue for a higher line. A 2023 paper from the American Society of Hematology's education programme says several lines of evidence suggest the body's physiological ferritin cut-off is 50 ng/mL, and that because 30 to 50% of healthy women have no marrow iron stores, setting a limit at the lowest 2.5% of a sample is "not appropriate"¹⁹. The BSG notes that 45 µg/L "has been suggested as providing the optimal trade-off between sensitivity and specificity"¹. A 2024 systematic review in Lancet Haematology states that under 30 µg/L has high sensitivity and specificity for diagnosing iron deficiency in adults, while the lower limits laboratories report are typically lower²⁰. These are positions in an open discussion, which the Bath guide describes as "debate within the literature regarding where the appropriate thresholds should be placed"³. They are not advice for any one person.

What usually happens next on the NHS

On the NHS, a GP usually starts with a full blood count and looks for the cause of iron deficiency anaemia before recommending treatment. If the blood count shows a low red blood cell count, the NHS says iron tablets are recommended, usually taken for about 6 months². It advises seeing a GP if you think you might have iron deficiency anaemia².

Intravenous iron is a separate route. The BSG recommends that it should be considered when oral iron is "contraindicated, ineffective or not tolerated", or when correcting iron deficiency anaemia is particularly urgent¹. Our guide to getting an iron infusion on the NHS or privately covers referral and waiting times.

Getting ferritin checked at our Mayfair clinic

We arrange blood tests that include ferritin at 27 Hill Street, Mayfair, with results in 24 to 48 hours. Our Well Woman and Well Man profiles both include ferritin, and blood testing at our Mayfair clinic can begin with a complimentary nurse consultation.

On our iron infusion page, the guideline is that we typically consider IV iron when ferritin is below 15 to 30 µg/L alongside relevant symptoms. We need a blood test from the last 3 months before going ahead, and the dose is set from your ferritin and weight. Our medical team reviews your results in a consultation and confirms the right path forward. The iron infusion page explains how an appointment works.

Common questions

Is a ferritin of 30 low?

A ferritin of 30 µg/L sits on the cut-off most UK guidance uses, and it is at or above the lower limit printed by 12 of the 13 laboratories we compared (York lists 30 at the boundary between its depletion and normal bands). The BSG describes levels under 30 µg/L as generally indicative of low iron stores¹. NHS Highland adds that 30 to 50 µg/L can still be consistent with iron deficiency, particularly in older patients and where inflammation is present⁹. What a result of 30 means for you depends on your symptoms, haemoglobin and inflammatory markers, so it is a question for your GP or clinician.

Can ferritin be low when haemoglobin is normal?

Yes: ferritin usually falls before haemoglobin does, so iron stores can be low while a blood count is still normal. The Bath guide says low ferritin "is usually first to appear and is very sensitive to detect iron deficiency"³. The BSG calls this non-anaemic iron deficiency and cites a study of young women with heavy periods in which over half had reduced iron stores but only 25% were anaemic¹.

Does a high ferritin mean I have plenty of iron?

Not necessarily, because ferritin also rises with inflammation, infection, liver disease and several other conditions. The Bath guide lists acute or chronic inflammation, kidney disease, heart failure, liver disease, excessive alcohol intake, malignancy and hyperthyroidism as causes of a raised result³. Where there is doubt, it suggests testing transferrin saturation as well³.