Ferritin levels in women have just been redefined. On September 16, 2026, the American Society of Hematology (ASH) published its first evidence-based guidelines for diagnosing iron deficiency, and the headline change is simple: the ferritin number below which you count as iron deficient has roughly doubled. For most adults, including menstruating and pregnant women, iron deficiency is now diagnosed at a ferritin of 30 ng/mL or lower, and at 50 ng/mL or lower for women at higher risk.
That matters because many lab reports still print a lower limit of around 12 to 15 ng/mL. A result of 22 ng/mL, flagged as normal last month, may now meet the definition of iron deficiency. In this article you’ll learn what exactly changed, how to reread a ferritin result that sits near the old cutoff, and what the new guidance does not say.
What the new ASH ferritin thresholds say
The guideline panel, chaired by pediatric hematologist Jacquelyn Powers of Texas Children’s Hospital, used the GRADE method to weigh the evidence and issued five recommendations covering young children, adults, menstruating and pregnant individuals, and people with inflammation. The ASH press release summarizes them as follows.
| Group | Common older cutoff | New ASH 2026 threshold for iron deficiency |
|---|---|---|
| Children 9 months to 4 years | About 12 ng/mL | 20 ng/mL or lower |
| Adults, menstruating or pregnant individuals | About 15 ng/mL | 30 ng/mL or lower |
| Higher-risk groups, such as heavy menstrual bleeding or anemia in pregnancy | No specific cutoff | 50 ng/mL or lower |
| Adults with inflammation (cancer, inflammatory bowel disease, infection) | Varied by specialty | Ferritin under 100 ng/mL or transferrin saturation under 20% |
One practical note: ng/mL and µg/L are the same unit, so a report that reads 28 µg/L means 28 ng/mL. The thresholds apply whether or not your hemoglobin is low. That is the real shift. Iron deficiency without anemia, the stage where stores are empty but red cells still look fine, is now easier to name.
Why a normal ferritin could still mean low iron
Ferritin is the protein that stores iron, and the blood level mirrors how much you have in reserve. The problem has always been the cutoff. Laboratory reference ranges are built by testing apparently healthy people, and a sizable share of menstruating women in those groups are quietly iron depleted. Their low values drag the bottom of the range down, so the printed lower limit ends up describing a common state rather than a healthy one. The effect is strongest for ferritin levels in women of reproductive age, because monthly blood loss keeps many of them close to empty.
You can see the gap in official material that predates the guideline. The National Heart, Lung, and Blood Institute page on iron deficiency anemia, last updated in 2022, still lists a normal ferritin range of 20 to 200 for women. Under the new guidance, a woman at 25 would sit inside that range and still meet the definition of iron deficiency.
Our guide explains in detail the causes and symptoms of low ferritin. What is new here is only the line where low begins.
Rereading ferritin levels in women after the change
If you have a recent result, check it against the new numbers rather than the range printed beside it. A rough reading guide:
- 30 ng/mL or lower: meets the new ASH definition of iron deficiency for adults, even with normal hemoglobin.
- 31 to 50 ng/mL: may still count as iron deficiency if you have heavy periods, iron deficiency symptoms, other risk factors, upcoming surgery, or plans for pregnancy.
- Above 50 ng/mL with no inflammation: iron stores are unlikely to be the explanation for your symptoms.
- Under 100 ng/mL with an inflammatory condition: iron deficiency is possible, because inflammation pushes ferritin up and hides low stores.
When ferritin can mislead
Ferritin rises with infection, inflammation, liver disease and obesity, so a normal-looking value does not always mean full stores. That is why the guideline adds transferrin saturation for people with inflammation. If your report includes it, our explainer covers what iron saturation levels mean. Seeing ferritin, serum iron and TIBC together is easier with our overview of the full iron studies panel.
The opposite problem, a ferritin that is too high, is not covered by this guideline. That picture is described in our article on high ferritin levels and their causes.
Who should ask about a ferritin test
ASH estimates that iron deficiency affects about 10 million adults in the United States, and that up to 70% of cases are missed in high-risk groups. Ferritin levels in women deserve particular attention, and the groups most worth checking are:
- women with heavy or prolonged periods;
- people who are pregnant or planning a pregnancy;
- anyone scheduled for major surgery;
- people on vegetarian or restrictive diets, and endurance athletes;
- people with celiac disease, inflammatory bowel disease or past stomach surgery;
- young children, especially between 9 months and 4 years.
Symptoms that often prompt the test include fatigue, shortness of breath on exertion, headaches, a racing heart, restless legs and hair shedding. Hair loss is a frequent trigger for a ferritin check, and this article reviews which blood tests matter for hair loss.
What the guideline does not change
These are diagnostic thresholds, not treatment instructions. ASH says separate guidance on treating iron deficiency is expected in 2027. A ferritin under the new cutoff is a reason to talk to your clinician, not a reason to start high-dose iron on your own. Iron supplements can cause digestive side effects, and taking them without a diagnosis can mask a bleeding source that needs investigation.
That last point matters most for men and for women after menopause. In these groups, new iron deficiency is less likely to come from diet and more likely to come from slow blood loss, often in the digestive tract. The number is only the start. Finding the cause is the medical work that follows.
Finally, not every lab will update its printed range at once. For a while, your report may still call a ferritin of 20 normal. Knowing the new guidance lets you raise it with your doctor.
Latest scientific advances
According to research indexed in PubMed, the move toward higher ferritin cutoffs has been building for several years, and recent studies explain why.
A 2024 study of more than 62,000 women in the US and Canada, published in JAMA Network Open, compared three definitions of iron deficiency. Using a ferritin cutoff of 25 instead of 15 roughly doubled the share of women aged 25 to 54 who counted as iron deficient. What this means for you: the definition, not your body, can decide whether you are told your iron is fine.
A 2025 Cleveland Clinic analysis in Clinical Biochemistry rebuilt ferritin reference ranges using only people with confirmed normal iron. The lower limit its standard method produced for women was around 17, while the cutoff that best separated iron-deficient from iron-replete women was far higher, near 45. In plain terms, the range printed on many lab reports is set too low for women.
A 2026 study of 907 blood donors in the British Journal of Haematology, led by CDC researchers, looked for the ferritin level at which red blood cell production first starts to suffer. It landed between about 25 and 32 depending on age and sex, close to the new 30 cutoff. An earlier CDC analysis in Blood Advances reached similar conclusions for pregnancy, suggesting about one more pregnant woman in ten would be recognized as iron deficient with physiology-based cutoffs.
One caution comes from a 2024 Swiss comparison of three common laboratory methods, published in Diagnostics: the same blood sample can give ferritin results that differ by up to about a third from one method to another. What this means for you: when you track ferritin over time, try to use the same laboratory.
When to talk to a doctor
Book a visit if your ferritin is 30 or lower, or up to 50 with heavy periods or pregnancy plans, especially if you have symptoms. Seek prompt care for black or bloody stools, vomiting blood, very heavy bleeding, chest pain, fainting, or breathlessness at rest. If you are a man or postmenopausal and your ferritin is low, ask how the cause will be investigated. Anemia itself is covered in our guide to anemia symptoms, causes and tests.
Glossary
| Term | Definition |
|---|---|
| Ferritin | The protein that stores iron. Its blood level reflects your iron reserves. |
| Iron deficiency without anemia | Low iron stores while hemoglobin is still in the normal range. |
| Transferrin saturation (TSAT) | The share of the iron transport protein that is carrying iron, useful when inflammation distorts ferritin. |
| Reference range | The span of values printed on a lab report, based on results from a comparison group. |
| GRADE | A standard method for rating the quality of evidence behind medical recommendations. |
| ng/mL | Nanograms per milliliter, the usual ferritin unit. It equals µg/L. |
Frequently asked questions
What is a normal ferritin level for a woman?
Under the 2026 ASH guidelines, a ferritin of 30 ng/mL or lower indicates iron deficiency in adult women, including during pregnancy. Above that, stores are generally considered adequate, although women with heavy periods or other risk factors may be assessed against a cutoff of 50. The range printed on your lab report may still show an older, lower limit.
Is a ferritin of 20 too low?
By the new ASH definition, yes. A ferritin of 20 ng/mL in an adult meets the threshold for iron deficiency even if hemoglobin is normal. Under older cutoffs of 12 to 15 it would often have been read as normal. Discuss it with your clinician, who will look at symptoms and possible causes.
What is a dangerously low ferritin level?
There is no single danger number. Very low values, often in the single digits, usually mean stores are exhausted and anemia may already be present. What makes a situation urgent is usually the cause and the symptoms, such as heavy bleeding, chest pain or fainting, rather than the ferritin figure alone.
Can you have low ferritin with normal hemoglobin?
Yes. This is iron deficiency without anemia, and it is common in menstruating women. Stores run down first, and hemoglobin falls only later. The new guidelines were written partly to catch this earlier stage, when symptoms such as tiredness or hair shedding may already appear.
Should I take iron if my ferritin is under 30?
Not without talking to a clinician first. The ASH guidance covers diagnosis only, with treatment recommendations expected in 2027. Your doctor will want to know why stores are low, choose a dose and form, and plan a recheck. Self-treating can hide a bleeding problem that needs attention.
Do the new thresholds apply to men?
Yes. The adult threshold of 30 ng/mL applies to all adults. In men and postmenopausal women, low ferritin more often signals blood loss, so the priority is finding the cause.
Sources
- American Society of Hematology. ASH Sets New Standards for Diagnosing Iron Deficiency. Press release, September 16, 2026. hematology.org
- American Society of Hematology. ASH Clinical Practice Guidelines on Iron Deficiency Anemia, 2026. hematology.org
- MedlinePlus, National Library of Medicine. Ferritin Blood Test. medlineplus.gov
- National Heart, Lung, and Blood Institute. Iron-Deficiency Anemia. nhlbi.nih.gov
- Barton JC, Wiener HW, Barton JC, Acton RT. Prevalence of Iron Deficiency Using 3 Definitions Among Women in the US and Canada. JAMA Network Open, 2024. doi.org
- Troike KM, McShane AJ. Re-evaluating ferritin thresholds to diagnose iron deficiency. Clinical Biochemistry, 2025. doi.org
- Addo OY, Brittenham GM, Mei Z, et al. Physiologically based serum hepcidin and ferritin thresholds identify similar onsets of iron-deficient erythropoiesis in adult blood donors. British Journal of Haematology, 2026. doi.org
- Mei Z, Addo OY, Jefferds MED, et al. Physiologically based trimester-specific serum ferritin thresholds for iron deficiency in US pregnant women. Blood Advances, 2024. doi.org
- Lemaire B, Frias MA, Golaz O, et al. Ferritin: A Biomarker Requiring Caution in Clinical Decision. Diagnostics, 2024. doi.org
Further reading
- Our guide details the causes and symptoms of low ferritin
- This overview explains the full iron studies panel
- Our explainer covers the transferrin blood test
- This article reviews the blood tests that matter for hair loss
- Our method walks through a complete reading of blood test results
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A ferritin result rarely comes alone. It sits next to hemoglobin, MCV, serum iron and transferrin saturation, and the new thresholds make that context more important. AI DiagMe reads your blood test report in plain language, explains what each value measures and flags what is worth raising with your doctor. It helps you understand your results; it does not diagnose and does not replace a healthcare professional.
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