Blood Tests for Hair Loss: Finding the Root Cause

Seeing more hair in your brush than usual? Hair loss in women often has an underlying medical cause that blood tests can help identify.

Common Causes of Hair Loss

• Thyroid dysfunction: Both hypo and hyperthyroidism cause hair loss
• Iron deficiency: One of the most common causes in women
• Hormonal imbalances: Excess androgens, perimenopause
• Nutrient deficiencies: B12, vitamin D, zinc, biotin
• Autoimmune conditions: Alopecia areata, lupus
• Stress: Telogen effluvium from major stressors

The Hair Loss Lab Panel

Thyroid

• TSH, Free T3, Free T4
• TPO and Thyroglobulin antibodies

Iron

• Ferritin (optimal >70 ng/mL for hair)
• Complete iron panel

Hormones

• Testosterone (total and free)
• DHEA-S
• Estradiol
• Progesterone

Nutrients

• Vitamin D
• Vitamin B12
• Zinc
• Biotin

Other

• ANA (antinuclear antibody) if autoimmune suspected
• CBC to check for anemia

The Ferritin-Hair Connection

Research shows that ferritin levels below 70 ng/mL may contribute to hair loss, even when hemoglobin is normal. Many dermatologists recommend ferritin >70 ng/mL for optimal hair health.

References

• Trost, L. B., et al. (2006). The diagnosis and treatment of iron deficiency and its potential relationship to hair loss. Journal of the American Academy of Dermatology, 54(5), 824-844.
• Kantor, J., et al. (2003). Decreased serum ferritin is associated with alopecia in women. Journal of Investigative Dermatology, 121(5), 985-988.
• Olsen, E. A., et al. (2010). Iron deficiency in female pattern hair loss, chronic telogen effluvium, and control groups. Journal of the American Academy of Dermatology, 63(6), 991-999.