Ferritin Longevity-Medicine Target Ranges: What the Evidence Says

What Ferritin Actually Measures

Ferritin is the body's primary intracellular iron-storage protein. A small fraction leaks into the bloodstream, and that serum level reflects total-body iron stores under normal conditions. One 2021 review in Nutrients confirmed that serum ferritin correlates reasonably well with bone-marrow iron in the absence of inflammation, making it the most practical non-invasive proxy for iron stores in clinical practice.

Why Standard Reference Ranges Are Not Enough

Most commercial labs flag ferritin as "normal" anywhere from 12 to 300 to 400 ng/mL. That span is wide enough to drive a truck through. A 28-year-old woman with a ferritin of 14 ng/mL technically falls inside reference range yet may have exhausted storage iron entirely, a state the WHO defines as depleted iron stores at ferritin <15 ng/mL. Treating the reference range as a clinical goal leaves a large middle ground where symptoms are real and tissue iron is suboptimal.

The Acute-Phase Reactant Problem

Ferritin rises during infection, autoimmune flares, liver disease, and metabolic syndrome, independent of iron stores. A ferritin of 180 ng/mL in a patient with an elevated C-reactive protein (CRP) may reflect inflammation rather than iron excess. A 2018 analysis in Clinical Chemistry demonstrated that CRP co-elevation substantially weakens the relationship between serum ferritin and true iron stores. Always interpret ferritin alongside CRP, and recheck after any acute illness resolves.

The Longevity-Medicine Case for 50 to 100 ng/mL

The longevity-medicine field converges on a ferritin target of roughly 50 to 100 ng/mL for non-pregnant adults who are not in an acute inflammatory state. This window is narrow by design: high enough to protect tissues from iron deficiency, low enough to limit iron-catalyzed oxidative stress.

Iron and Oxidative Stress

Free iron participates in the Fenton reaction, converting hydrogen peroxide to the hydroxyl radical, one of the most reactive oxygen species in biology. A 2020 paper in Free Radical Biology and Medicine described how iron overload accelerates lipid peroxidation and mitochondrial dysfunction in aging tissues. Keeping ferritin in the lower half of the reference range reduces the substrate available for this reaction without producing iron deficiency.

Population Data on All-Cause Mortality

A large Korean cohort study (N=12,033) published in the Journal of Clinical Medicine in 2021 found a U-shaped relationship between serum ferritin and all-cause mortality, with the lowest mortality risk concentrated between 40 and 100 ng/mL. That analysis is indexed at PubMed here. The finding held after adjustment for age, sex, CRP, and kidney function.

Sex-Specific Considerations

Pre-menopausal women lose iron monthly through menstruation and are far more likely to present with ferritin <30 ng/mL than with excess. Post-menopausal women and men accumulate iron over decades; their risk profile shifts toward the upper end. The NHANES III analysis (N=11,646) found that ferritin levels rise steadily in men throughout adulthood and in women after menopause, with median values in older men exceeding 150 ng/mL. That age-related accumulation is one reason longevity clinicians set an upper target well below the conventional reference ceiling.

Ferritin and Hair Loss

Ferritin <30 ng/mL is consistently associated with telogen effluvium and non-scarring alopecia in women. Short answer: most dermatologists now target ferritin >50 ng/mL before concluding that iron status is not contributing to shedding.

What the Dermatology Literature Shows

A 2023 systematic review in the Journal of the American Academy of Dermatology analyzed 13 studies and concluded that low ferritin is a clinically relevant, modifiable risk factor for female-pattern hair thinning. The authors noted that the optimal repletion threshold has not been established by randomized trial, but observational data favor a target above 40 to 70 ng/mL.

Practical Threshold for Hair Regrowth

Many practitioners use 50 ng/mL as the minimum and 70 to 100 ng/mL as the repletion goal when hair loss is the presenting complaint. Below 30 ng/mL, oral iron supplementation is typically warranted; between 30 and 50 ng/mL, the clinical judgment depends on symptoms, diet, and menstrual blood loss. A 2017 review in Dermatology Practical and Conceptual supported this tiered approach, noting that ferritin between 30 and 70 ng/mL represents a gray zone where dietary optimization alone may suffice in women with light cycles.

Ferritin and Restless Legs Syndrome

Low brain iron is the best-established modifiable driver of restless legs syndrome (RLS). Serum ferritin below 50 to 75 ng/mL predicts worse RLS severity in both primary and secondary cases.

Mechanism and Clinical Evidence

Dopaminergic neurons in the substantia nigra depend on iron as a cofactor for tyrosine hydroxylase, the rate-limiting enzyme in dopamine synthesis. When ferritin drops, central dopamine signaling deteriorates, and the urge-to-move sensation characteristic of RLS intensifies. A 2020 guideline update from the American Academy of Sleep Medicine recommended checking ferritin in all RLS patients and repleting to at least 75 ng/mL (ideally 100 ng/mL) before escalating to dopamine-agonist therapy.

IV Iron in Refractory RLS

When oral iron fails to raise ferritin above 75 ng/mL within 3 months, intravenous iron sucrose or ferric carboxymaltose becomes a clinically reasonable option. A 2019 randomized controlled trial (N=290) in Sleep Medicine showed that a single infusion of ferric carboxymaltose 1,000 mg improved International Restless Legs Scale scores by 6.4 points more than placebo at 4 weeks (P<0.001). The effect was largest in participants with baseline ferritin below 100 ng/mL.

Ferritin and Cardiovascular Risk

The relationship between ferritin and cardiovascular disease is real but complicated by inflammation. Elevated ferritin above 200 ng/mL, when CRP is normal, signals iron excess that may independently contribute to atherosclerosis.

The Iron Hypothesis of Atherosclerosis

Jerome Sullivan first proposed in 1981 that body iron stores accelerate coronary artery disease by promoting LDL oxidation. Subsequent data have been mixed, but a 2019 meta-analysis in Arteriosclerosis, Thrombosis, and Vascular Biology (19 studies, N=286,119) found that each 100 ng/mL increment in serum ferritin was associated with a 4% higher risk of type 2 diabetes, which mediates some of the cardiovascular signal.

Metabolic Syndrome and Non-Alcoholic Fatty Liver Disease

Ferritin rises in both metabolic syndrome and non-alcoholic fatty liver disease (NAFLD) through a combination of true iron loading and inflammatory release. A 2021 analysis in Hepatology Communications reported that ferritin >200 ng/mL in men and >150 ng/mL in women with NAFLD predicted more advanced fibrosis on biopsy, independent of transferrin saturation. In that population, ferritin is partly a severity marker, not purely a storage marker.

The Hemochromatosis Screening Threshold

Hereditary hemochromatosis (HH), caused by HFE gene mutations, produces progressive iron loading that destroys joints, liver, heart, and endocrine glands. The AASLD guidelines on hemochromatosis recommend genetic testing when ferritin exceeds 300 ng/mL in women or 400 ng/mL in men AND transferrin saturation exceeds 45%. Catching HH before ferritin climbs above 1,000 ng/mL prevents cirrhosis in the majority of patients.

How to Interpret Your Ferritin Result

Accurate interpretation requires at least three simultaneous data points: serum ferritin, transferrin saturation, and CRP.

Reading the Numbers Together

• Ferritin <15 ng/mL + low transferrin saturation: iron-deficiency, likely dietary or blood-loss driven.
• Ferritin 15 to 50 ng/mL + normal CRP: functional iron deficiency; symptoms (fatigue, hair loss, RLS) are common.
• Ferritin 50 to 100 ng/mL + normal CRP: optimal longevity-medicine window.
• Ferritin 100 to 200 ng/mL + normal CRP: mildly elevated; lifestyle review (red-meat intake, alcohol) is appropriate.
• Ferritin >200 ng/mL + elevated CRP: interpret cautiously; inflammation is likely inflating the reading.
• Ferritin >300 ng/mL (women) or >400 ng/mL (men) + high transferrin saturation: screen for HFE mutations.

Oral Iron Supplementation Protocols

For ferritin below 30 ng/mL without active bleeding, oral ferrous sulfate 325 mg (containing 65 mg elemental iron) taken every other day on an empty stomach is standard. A 2017 RCT in Lancet Haematology (N=90) showed that alternate-day dosing raised serum ferritin more efficiently than daily dosing by reducing hepcidin suppression between doses, resulting in 40% greater fractional iron absorption per dose. Recheck ferritin at 8 to 12 weeks.

Phlebotomy for Iron Reduction

When ferritin persistently exceeds 200 ng/mL without inflammation and HH is confirmed, therapeutic phlebotomy (removing 450 to 500 mL blood every 1 to 2 weeks) is the treatment of choice. The European Association for the Study of the Liver (EASL) 2022 clinical practice guidelines recommend phlebotomy to achieve ferritin below 50 ng/mL and maintain it below 100 ng/mL for long-term protection against cirrhosis and hepatocellular carcinoma.

Dietary and Lifestyle Factors That Affect Ferritin

Diet is the most accessible lever for managing ferritin in both directions.

Raising Ferritin Through Diet

Heme iron from red meat and organ meats is absorbed at 15 to 35%, compared to 2 to 20% for non-heme iron from plants. A 2020 review in Nutrients documented that consuming 100 mg vitamin C alongside a non-heme iron source roughly doubles absorption by reducing ferric iron to the more absorbable ferrous form. Tea and coffee consumed within 1 hour of meals reduce non-heme iron absorption by 60 to 90% through polyphenol binding.

Lowering Ferritin Through Diet and Lifestyle

For patients in the 150 to 250 ng/mL range without confirmed HH, practical steps include:

• Reducing red-meat intake to 2 to 3 servings per week.
• Avoiding iron-fortified cereals if total dietary iron intake is already adequate.
• Limiting alcohol, which stimulates intestinal iron absorption and hepatic ferritin release.
• Donating blood regularly. Blood donors have ferritin levels roughly 30% lower than non-donors in cross-sectional studies, as confirmed in a 2019 analysis in Transfusion.

Exercise and Ferritin

Endurance athletes often present with low ferritin (below 30 ng/mL) due to increased iron turnover, gastrointestinal microbleeding from running, foot-strike hemolysis, and elevated hepcidin after training sessions. Testing ferritin at least 48 hours after a hard workout reduces the transient post-exercise elevation and gives a cleaner baseline reading.

Special Populations

Pregnancy

Iron requirements approximately double in pregnancy. The CDC recommends routine iron supplementation of 30 mg elemental iron daily for all pregnant women, with higher doses when ferritin falls below 30 ng/mL. Ferritin below 15 ng/mL in the second trimester is associated with preterm delivery and low birth weight in multiple cohort studies.

Older Adults

Ferritin rises with age partly because chronic low-grade inflammation (inflammaging) releases intracellular stores. A 2020 paper in Age and Ageing found that ferritin above 200 ng/mL in adults over 65 years was independently associated with frailty, even after excluding known inflammatory diseases. The longevity-medicine target of 50 to 100 ng/mL applies equally to this age group, with the caveat that CRP must always be checked.

Patients on GLP-1 Receptor Agonists

Semaglutide and tirzepatide reduce food intake substantially, and if protein and micronutrient intake drops significantly, iron absorption may fall over months of therapy. Checking ferritin at baseline and at 6-month intervals is a reasonable precaution for patients on GLP-1 therapy who have any history of low ferritin, heavy periods, or vegetarian diets.