Ferritin
For informational purposes only — not medical advice. Always consult a qualified healthcare provider before making changes to your health regimen. Full disclaimer →
- Ferritin is the best marker of iron status — it reflects stored iron far more accurately than serum iron alone, which fluctuates hour to hour based on recent meals and diurnal variation.
- Longevity-optimal target: 50–100 ng/mL. Standard ranges extend up to 300+ ng/mL for men — levels that are technically 'normal' but associated with meaningfully elevated oxidative stress and cardiovascular risk.
- High ferritin can mean iron overload OR inflammation — always investigate which. Never treat high ferritin with dietary iron restriction before ruling out an inflammatory cause. Pair with hsCRP and transferrin saturation to distinguish.
- Low ferritin causes symptoms well before anemia. Fatigue, brain fog, cold intolerance, hair loss, and poor exercise tolerance can occur with ferritin below 30 ng/mL even when hemoglobin is normal.
- Iron is a potent oxidant at high levels. Free iron catalyzes free radical production via the Fenton reaction — one of the primary mechanisms linking high ferritin to accelerated aging and cardiovascular damage.
Understanding Ferritin: Iron Storage and the Oxidative Burden of Excess
Ferritin is one of the most clinically valuable markers on a standard blood panel — and one of the most commonly misinterpreted. Most people who track their health know that low ferritin causes fatigue and anemia. Far fewer understand that high ferritin, even within the broad "normal" reference range, carries its own set of serious risks. Getting ferritin right requires understanding both ends of the spectrum.
At its core, ferritin is a storage protein. Each ferritin molecule can hold up to 4,500 iron atoms, sequestering them safely inside cells until they are needed for hemoglobin synthesis, enzyme function, and energy production. A small fraction of this intracellular ferritin leaks into the bloodstream, where it can be measured — giving clinicians a reliable window into total body iron stores. A low serum ferritin reliably indicates depleted iron stores. A high ferritin indicates either iron excess or, critically, an inflammatory response that is elevating ferritin independently of iron status.
This dual nature — ferritin as both an iron marker and an inflammatory marker — is why interpretation requires context. A ferritin of 250 ng/mL in a man with elevated hsCRP and metabolic syndrome means something entirely different from a ferritin of 250 ng/mL in a man with hereditary hemochromatosis and elevated transferrin saturation. The treatment implications are opposite.
Standard Reference Ranges vs. Longevity-Optimal Ranges
Standard laboratory reference ranges for ferritin are extraordinarily wide — designed to catch frank iron deficiency and overt iron overload disorders, not to optimize health. For men, most labs flag anything between 24 and 336 ng/mL as normal. For women, the range is typically 11 to 307 ng/mL. A man with ferritin of 320 ng/mL is technically in range, yet research suggests this level is associated with meaningfully elevated cardiovascular risk, insulin resistance, and oxidative stress.
| Category | Ferritin Level | Standard Interpretation | Longevity Assessment |
|---|---|---|---|
| Deficient | < 12 ng/mL | Iron deficiency | Depleted — anemia risk, significant functional impairment |
| Low-normal | 12–49 ng/mL | Normal | Monitor — symptoms may be present; optimize toward 50+ |
| Longevity-optimal | 50–100 ng/mL | Normal | Optimal — adequate stores, minimal oxidative burden |
| Elevated | 101–200 ng/mL | Normal | Monitor — investigate inflammatory cause; reduce if iron excess confirmed |
| High | > 200 ng/mL | Normal to borderline | Elevated risk — workup required; transferrin saturation + hsCRP essential |
The epidemiological data supporting a tighter target is substantial. A large prospective study published in BMC Medicine found a U-shaped relationship between ferritin and all-cause mortality — risk rising at both ends of the distribution, with the nadir in the 50–100 ng/mL range. 1 Separate analyses have linked ferritin above 200 ng/mL to a 2–3-fold increase in type 2 diabetes risk, and ferritin above 300 ng/mL in men to significantly elevated cardiovascular event rates — even after controlling for known cardiovascular risk factors.
Already have your lab results? See how your ferritin and other markers score on a longevity scale — in under 60 seconds.
Analyze My Biomarkers →Why High Ferritin Accelerates Aging: The Iron-Oxidation Connection
Iron is essential for life, but free iron is one of the most potent pro-oxidants in biology. This is why the body invests heavily in iron-binding proteins — transferrin in the blood, ferritin in cells — to keep iron sequestered and prevent it from participating in uncontrolled oxidative chemistry.
When iron stores become chronically elevated, the capacity of these binding proteins can be exceeded, leaving a pool of loosely bound or "labile" iron available to catalyze the Fenton reaction — a chemical process that converts hydrogen peroxide into hydroxyl radicals, among the most reactive and damaging molecules in the body. Hydroxyl radicals attack DNA, oxidize LDL particles (converting them into the form most likely to deposit in artery walls), damage mitochondrial membranes, and promote cellular senescence.
This mechanism links chronically elevated iron stores to several aging-related conditions:
- Cardiovascular disease: Oxidized LDL is a primary driver of atherosclerosis. High ferritin also promotes endothelial dysfunction and arterial stiffness through iron-mediated oxidative stress independent of LDL cholesterol levels.
- Insulin resistance and type 2 diabetes: Iron accumulates in pancreatic beta cells and liver tissue, impairing insulin secretion and hepatic insulin sensitivity. Population studies consistently find ferritin in the upper quartile of normal associated with 2–3 times the diabetes risk of ferritin in the lower quartile.
- Liver disease: Excess iron accumulation in hepatocytes drives oxidative damage, inflammation, and fibrosis — independent of alcohol consumption. Non-alcoholic fatty liver disease frequently co-occurs with elevated ferritin, and iron overload accelerates the progression from simple steatosis to steatohepatitis.
- Neurodegeneration: Iron accumulates in the substantia nigra, hippocampus, and cortex with aging. Elevated iron burden is implicated in Parkinson's disease and Alzheimer's disease pathology, and iron chelation has been investigated as a neuroprotective strategy in preclinical models.
- Cancer: Iron promotes cell proliferation and is preferentially taken up by rapidly dividing cells. High ferritin has been associated with increased colorectal, liver, and breast cancer risk in prospective studies.
A particularly compelling line of evidence comes from studies of blood donors. Regular blood donation — which removes iron from the body — is associated with lower ferritin, reduced oxidative stress markers, and in some studies, lower rates of myocardial infarction and all-cause mortality. This is consistent with a causal role for iron in aging-related disease, not merely correlation.
The Other End: Why Low Ferritin Matters Before Anemia Develops
The conventional view of iron deficiency focuses on anemia — the point at which hemoglobin drops and red blood cells become small and pale. But iron depletion causes significant functional impairment well before this stage, during the period when iron stores are depleted but hemoglobin is still maintained.
This is because iron-dependent functions extend far beyond oxygen transport. Iron is a cofactor in the mitochondrial electron transport chain, making it essential for cellular energy production. It is required by ribonucleotide reductase, the enzyme that synthesizes DNA precursors for cell division. It activates thyroid peroxidase, the enzyme that converts inactive T4 to active T3 thyroid hormone — explaining why iron deficiency frequently causes or worsens hypothyroid symptoms even when TSH looks normal. And it is a structural component of myoglobin in muscle tissue, directly affecting muscle contractility and endurance capacity.
The practical consequence: a person with ferritin of 18 ng/mL and normal hemoglobin may be experiencing significant fatigue, reduced VO2 max, hair shedding, cold intolerance, brain fog, and restless legs — and be told by their doctor that their blood work is "fine" because anemia hasn't yet developed. In the longevity medicine context, the target of 50+ ng/mL is chosen specifically to prevent this pre-anemic depletion state.
Iron deficiency without anemia is especially common in:
- Premenopausal women, particularly those with heavy menstrual cycles
- Endurance athletes (especially runners, due to foot-strike hemolysis and increased turnover)
- People following predominantly plant-based diets (non-heme iron from plants is absorbed at roughly 2–5% vs. 15–35% for heme iron from meat)
- People with gastrointestinal conditions affecting absorption (celiac disease, IBD, low stomach acid)
- Frequent blood donors who don't adequately replenish iron
Interpreting a High Ferritin: Inflammation vs. Iron Overload
Before acting on an elevated ferritin result, the first question is always: is this iron overload, or is this inflammation driving ferritin up? The distinction matters enormously for treatment.
The key investigation is transferrin saturation — the percentage of transferrin (the iron transport protein) that is carrying iron. Normal transferrin saturation is 20–45%. If ferritin is high and transferrin saturation is also high (>45%), true iron overload is likely — including possible hereditary hemochromatosis, which affects approximately 1 in 200 people of Northern European descent. If ferritin is high but transferrin saturation is normal or low, inflammation is the most probable explanation.
Pairing ferritin with hsCRP adds further clarity. Elevated hsCRP alongside elevated ferritin points strongly toward an inflammatory driver. In this scenario, the priority is identifying and addressing the source of inflammation — metabolic syndrome, excess adiposity, alcohol, occult infection, autoimmune activity — rather than attempting to lower iron directly.
If hereditary hemochromatosis is suspected based on high ferritin and high transferrin saturation, genetic testing for HFE gene variants (C282Y and H63D) is the appropriate next step, ordered through a physician.
How to Test Ferritin
Ferritin is a standard blood test available at any clinical laboratory and is often included in comprehensive metabolic panels. Unlike fasting glucose or lipids, ferritin does not require fasting before the draw, though acute illness or recent vaccination can transiently elevate ferritin — so testing during a period of normal health gives the most representative result.
For a complete iron status picture, order alongside:
- Serum iron
- Transferrin saturation (TIBC or UIBC + serum iron)
- hsCRP — to contextualise an elevated ferritin result
Through a longevity testing service like InsideTracker, ferritin is included alongside a full metabolic, inflammatory, and hormonal panel — giving the context needed to interpret it correctly. If you specifically need to retest ferritin to track progress, Ulta Lab Tests offers it as a direct-access test for $15–25 without a doctor's visit.
Retesting frequency depends on your baseline. If ferritin is in the optimal range, annual retesting as part of a comprehensive panel is sufficient. If actively working to raise low ferritin through dietary and supplementation changes, retest at 90 days to assess response. If addressing high ferritin through blood donation or dietary changes, retest every 60–90 days until stable.
Sources
- Ellervik C, et al. "Elevated Transferrin Saturation and Risk of Diabetes: Three Population-Based Studies." Diabetes Care, 2011. PubMed →
- Orban E, et al. "Association Between Serum Ferritin and Cardiovascular Mortality in the General Population." European Heart Journal, 2014. PubMed →
- Beutler E, et al. "Genetic Basis of Hereditary Hemochromatosis." Proceedings of the National Academy of Sciences, 1996. PubMed →
| Range Type | Value (ng/mL) | Notes |
|---|---|---|
| Standard Clinical Range | Male: 24–336 ng/mL · Female: 11–307 ng/mL | Designed to identify disease risk — not longevity optimisation. |
| Longevity-Optimal Target | 50–100 ng/mL (both sexes) |
Associated with reduced all-cause mortality and extended healthspan.
The longevity medicine community targets a tighter range than standard labs — high enough to ensure adequate iron stores and avoid deficiency symptoms, low enough to minimize the oxidative iron burden. Levels above 150–200 ng/mL warrant investigation even when technically 'normal.'
|
Already have your results? See what your Ferritin and other markers reveal about your longevity in 60 seconds.
Analyze My Labs →Affiliate disclosure: we may earn a commission if you purchase through these links at no extra cost to you.
What is the optimal ferritin level for longevity?
The longevity medicine community generally targets 50–100 ng/mL for both men and women. This range is high enough to prevent iron deficiency symptoms and support optimal energy, thyroid function, and cognitive performance, while remaining low enough to minimize the oxidative burden associated with excess stored iron. Standard lab reference ranges are much wider — up to 336 ng/mL for men — because they are calibrated to detect disease, not to optimize healthspan. Research consistently shows that cardiovascular risk, insulin resistance, and all-cause mortality begin rising at ferritin levels well within the 'normal' range.
Can ferritin be high even if I don't have iron overload?
Yes — and this is one of the most important things to understand about ferritin interpretation. Because ferritin is an acute-phase reactant, levels rise in response to any systemic inflammation, liver disease, alcohol use, obesity, metabolic syndrome, or infection — independent of actual iron stores. Someone with normal or even low iron can have a ferritin of 300+ ng/mL due to chronic low-grade inflammation. This is why high ferritin should never be treated with dietary iron restriction before ruling out an inflammatory cause. The correct workup includes serum iron, transferrin saturation, and an inflammatory marker like hsCRP. If transferrin saturation is low or normal alongside high ferritin, inflammation is the likely driver.
What are the symptoms of low ferritin?
Low ferritin causes a recognizable cluster of symptoms even when hemoglobin is still technically normal — a condition called iron deficiency without anemia. Common symptoms include persistent fatigue, reduced exercise capacity (especially endurance), difficulty concentrating, brain fog, hair thinning or shedding, cold hands and feet, restless legs syndrome, and an impaired ability to convert T4 to active T3 thyroid hormone. Many people with ferritin below 20–30 ng/mL are told their labs are 'fine' because their hemoglobin hasn't dropped yet — but the tissue-level iron depletion is already producing significant functional impairment. Symptoms typically resolve once ferritin rises above 50 ng/mL.
What causes chronically elevated ferritin?
The most common causes of persistently high ferritin are chronic inflammation (metabolic syndrome, obesity, non-alcoholic fatty liver disease, autoimmune conditions), regular alcohol consumption, hereditary hemochromatosis (a genetic condition causing excessive iron absorption), frequent red meat consumption in individuals with HFE gene variants, and liver disease. Less commonly, very high ferritin (above 1000 ng/mL) can indicate serious conditions including adult-onset Still's disease, hemophagocytic lymphohistiocytosis, or certain cancers. For most people with moderately elevated ferritin (150–400 ng/mL), metabolic inflammation and lifestyle factors are the primary drivers.
How do you lower ferritin if it's truly elevated due to iron overload?
If high ferritin is confirmed to reflect true iron excess (elevated transferrin saturation, no inflammatory cause), the most effective interventions are regular blood donation (which removes iron directly and is the primary treatment for hereditary hemochromatosis), reducing dietary heme iron from red meat, and avoiding iron-containing supplements. Phlebotomy — therapeutic blood removal — is the standard medical treatment for hereditary hemochromatosis and can reduce ferritin by 30–50 ng/mL per session. Some longevity practitioners recommend periodic blood donation for healthy adults with ferritin above 150–200 ng/mL as a preventive measure, though this remains an area of ongoing debate.