What Blood Test for Hair Loss: Key Markers to Check

If you are losing hair and wondering what blood test for hair loss can help identify the root cause, the direct answer is a comprehensive panel that includes iron (ferritin), thyroid-stimulating hormone (TSH), vitamin D, sex hormones (testosterone, DHEA-S), and a complete blood count (CBC). Today, clinical guidelines emphasize early detection of nutritional and hormonal imbalances to reverse shedding before follicles miniaturize. At Any Lab Test Now, we empower you to order these specific labs without a doctor visit, giving you actionable data to discuss with your healthcare provider.

Understanding Hair Loss and Diagnostic Lab Work

Hair loss affects over 50 million men and 30 million women in the US alone. While genetics play a role, many cases stem from treatable deficiencies or endocrine disorders. The right blood test for hair loss can differentiate between telogen effluvium, androgenetic alopecia, and alopecia areata. Today, updated clinical protocols recommend testing these core biomarkers first.

Iron and Ferritin Levels

Low ferritin (below 30 ng/mL) is a leading cause of hair thinning, especially in women. Ferritin stores iron for hair follicle growth. A simple iron panel plus ferritin is essential. The American Academy of Dermatology now suggests ferritin above 70 ng/mL for optimal hair cycling.

Thyroid Function (TSH, Free T3, Free T4)

Both hypothyroidism and hyperthyroidism trigger diffuse hair loss. TSH is the first-line screening. If TSH is outside the 0.5–4.5 mIU/L range, deeper thyroid markers are needed. Today, many labs also include anti-thyroid antibodies to rule out Hashimoto’s disease.

Vitamin D and B12

Vitamin D deficiency (below 30 ng/mL) is linked to alopecia areata. B12 deficiency can cause premature graying and shedding. These are inexpensive, high-yield tests that often get overlooked.

Sex Hormones (Testosterone, DHEA-S, SHBG)

Androgenetic alopecia involves sensitivity to dihydrotestosterone (DHT). While DHT is rarely tested directly, total and free testosterone, along with sex hormone-binding globulin (SHBG), provide insight. In women, elevated free testosterone may indicate PCOS, a common driver of hair thinning.

Complete Blood Count (CBC) and Inflammatory Markers

A CBC checks for anemia (low hemoglobin), which starves hair follicles of oxygen. C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) can flag chronic inflammation that disrupts the hair cycle.

Recommended Blood Test Panel for Hair Loss

To simplify your journey, we offer a curated panel that combines all critical markers. Below is a summary of what each component evaluates:

Key Steps After Your Blood Test for Hair Loss

• Review results with a primary care doctor or dermatologist who can interpret patterns.
• If ferritin is low, begin iron supplementation under medical guidance (avoid overload).
• For thyroid abnormalities, confirm with free T3 and T4, then discuss medication.
• Address vitamin D deficiency with 2,000–5,000 IU daily and recheck in 3 months.
• If hormones are imbalanced, consider endocrine referral for PCOS or menopause management.

When to Retest

Most providers recommend retesting 3–6 months after starting treatment. Hair regrowth is slow; visible improvement may take 4–6 months. Today, telemedicine follow-ups are common, and having your own lab data speeds up the process.

Why Choose Any Lab Test Now for Your Hair Loss Blood Work

We provide direct-access lab testing with no insurance or referral required. Our nationwide network of CLIA-certified labs ensures accurate results within 24–48 hours. The hair loss panel is available at our hair loss panel order page. You can also build a custom panel if you need additional markers like zinc or copper. Empower yourself with data to stop shedding and restore growth.