How to treat hair loss due to low ferritin (iron) levels?

Treatment of Hair Loss Due to Low Ferritin

Iron supplementation should be initiated for patients with documented iron deficiency (ferritin ≤15 μg/L) and hair loss, particularly when started within 6 months of onset for optimal prognosis. 1, 2

Diagnostic Workup

Essential Laboratory Testing

• Order CBC, serum ferritin, TSH, and transferrin saturation as baseline tests for any woman presenting with hair loss 1, 3
• Serum ferritin is the single most important test for assessing iron stores, with ferritin ≤15 μg/L confirming iron deficiency with 98% specificity in premenopausal women 1, 3
• Check transferrin saturation if ferritin appears "normal" (15-60 ng/mL) but microcytic anemia or low MCV is present, as ferritin can be falsely elevated during infection or inflammation 3, 4
• Consider tissue transglutaminase (TTG) antibodies if unexplained iron deficiency is found to rule out celiac disease 3

Critical Interpretation Pitfalls

• Ferritin can be falsely elevated during infection, inflammation, or chronic disease, potentially masking true iron deficiency 3, 4
• If ferritin is in the 15-60 ng/mL range with microcytic anemia, iron deficiency may still be present and requires additional testing with transferrin saturation and serum iron/TIBC 3
• Some evidence suggests ferritin levels ≥60 ng/mL (corresponding Hb ≥13.0 g/dL) may be optimal for hair growth, though this is not universally accepted 2

Treatment Approach

When to Treat with Iron Supplementation

Definitive indication: Iron deficiency anemia (ferritin ≤15 μg/L with anemia) should always be treated regardless of hair loss type 1, 4

Controversial but recommended: Treating iron deficiency without anemia (ferritin ≤15 μg/L, normal hemoglobin) is controversial, but the American Academy of Dermatology and Cleveland Clinic Foundation practice patterns support treatment in the context of hair loss 1, 4

Timing Considerations

• Iron supplementation started within 6 months of hair loss onset results in better prognosis 1, 2
• Hair loss due to iron deficiency develops gradually over months, not acutely 1, 3

Practical Treatment Protocol

• Provide adequate dietary iron intake and oral iron supplementation 4
• Monitor hair condition, ferritin, and hemoglobin levels every 3 months after supplementation 2
• Continue supplementation until ferritin normalizes (>15-20 μg/L minimum, though some advocate for >60 ng/mL) 2, 5
• Avoid excessive iron supplementation to prevent iron overload, especially in high-risk patients with hereditary hemochromatosis 4

Evidence Quality and Nuances

Conflicting Evidence on Iron-Hair Loss Relationship

The evidence for iron supplementation improving hair loss is mixed:

• Supporting evidence: Multiple studies found lower ferritin levels in patients with diffuse hair loss, telogen effluvium, and androgenetic alopecia 6, 7, 2
• Contradictory evidence: A 2002 British study found no clear association between low serum ferritin (≤20 μg/L) and chronic diffuse telogen hair loss, with iron supplementation failing to reverse hair loss in 5 women with low ferritin and normal scalp histology 5
• For alopecia areata specifically: Most studies show no difference in ferritin levels between alopecia areata patients and controls, with the British Association of Dermatologists stating routine iron testing is not recommended for alopecia areata 8, 1

Clinical Judgment Required

• There is insufficient evidence to recommend universal screening for iron deficiency in all patients with hair loss 4
• There is insufficient evidence to recommend iron supplementation for patients with hair loss and iron deficiency in the absence of anemia, though many experts do so based on clinical judgment 4
• The Cleveland Clinic Foundation screens both male and female patients with cicatricial and noncicatricial hair loss for iron deficiency, believing treatment for hair loss is enhanced when iron deficiency is treated, even without anemia 4

Identify and Treat Underlying Cause

• In premenopausal women, evaluate for menstrual blood loss and pregnancy 4
• In men and postmenopausal women, evaluate for gastrointestinal blood loss and malabsorption (including colon cancer screening) 4
• Patients who do not respond to iron replacement require additional testing to identify other underlying causes 4