Hair loss in women affects more than appearance. It usually indicates internal dysfunction. Statistics show that about 40 percent of women lose hair aged 50 and many experience hair shedding at a younger age.

Causes are typically associated with hormonal imbalance, nutritional deficiencies, stress, or auto-immune. In contrast to shampoos and oils, which act externally only, the blood tests will enable doctors to reveal the inner cause.

This guide explains the most important blood tests for hair loss in females. It shows why each test matters and how the results can shape treatment. It also covers what happens when all test results look normal but hair loss still continues.

The information on these tests will guide women on better options of restoring hair strength and growth.

Contents hide

What Causes Hair Loss in Females?

Types Of Hair Loss

Can Blood Work Determine Hair Loss?

What Blood Test Should Be Done For Hair Loss In Females?

What Is The Female Hormone Blood Test For Hair Loss?

Iron & Ferritin: Key Markers in Hair Fall

Why Women Have Low Ferritin:

CBC Test for Hair Loss: What It Tells You

Example:

Thyroid Function Tests and Female Hair Loss

Vitamin Deficiency Blood Tests Related to Hair Health

Mineral Deficiency Blood Tests for Hair Loss

Does Alopecia Show Up in Blood Tests?

What If All Blood Tests Are Normal But Hair Loss Continues?

Interpreting Blood Work for Hair Loss in Females

When Should You See a Doctor?

Can Men Also Get Hair Loss Blood Tests?

Hair Loss Treatment Options Based on Blood Test Results

Tips to Prepare for Blood Tests for Hair Loss

Additional Diagnostic Tools Besides Blood Work

Conclusion

Frequently asked questions

What Causes Hair Loss in Females?

Women’s hair loss is usually because of an internal imbalance instead of the surface damage. According to a research these are the most common factors:

Hormonal imbalance as a result of PCOS, menopause, pregnancy or thyroid disease.
Telogen effluvium caused by stress/trauma.
Autoimmune conditions such as alopecia areata or lupus.
Nutrient Deficiencies such as iron, ferritin, vitamin D, B12 or zinc.
Female pattern baldness that has a family tendency and is worsened by hormones.
Drugs like antidepressants, retinoids or blood thinners.
Crash diets or sudden weight loss.

Types Of Hair Loss

Diffuse Thinning: Spread across the scalp.
Patchy Bald Spots: Linked to autoimmune causes.
Widening Part Line: Common in female pattern baldness.

Since these causes overlap, doctors often depend on blood tests to separate them. Without knowing the root cause, even expensive hair products may not work.

Can Blood Work Determine Hair Loss?

Yes, blood work is crucial because hair is a mirror of internal health. The scalp and the follicles are very sensitive to changes in hormones, nutrition, and the immune system.

Why Blood Tests Matter:

Detect Hidden Deficiencies – iron, ferritin, vitamin D and B12
Reveal Hormonal Fluctuations – estrogen, testosterone, thyroid hormones
Spot Inflammation Or Immune Dysfunction – autoimmune disorders linked to alopecia
Guide Treatment – helps avoid “trial and error” with shampoos or supplements

What Blood Tests Can Show:

Low Ferritin – iron deficiency anemia.
High Tsh – underactive thyroid (hypothyroidism).
Low Vitamin D – linked with autoimmune hair loss.
High Testosterone/DHEA-S – female pattern baldness.
High Ana/Esr – autoimmune activity.

What Blood Test Should Be Done For Hair Loss In Females?

Physicians tend to prescribe a combination of tests rather than a single one because hair loss is not typically caused by a single aspect. The tests measure conditions of blood, the level of hormones, vitamins, minerals and immune system.

Test Name	What It Checks	Why It Matters
CBC	Red/white cells, hemoglobin	Checks anemia or infections
Ferritin	Iron stores	Low ferritin can cause thinning
TSH, T3, T4	Thyroid levels	Imbalance may trigger shedding
Vitamin D	Bone and immune health	Linked to excess hair fall
B12, Folate	Red cell production	Needed for growth
Zinc & Biotin	Cell repair and keratin	Help support healthy strands
DHEA, Testosterone	Androgens	Related to female pattern baldness
ANA, ESR	Inflammation or immune problems	May point to alopecia or hidden illness

What Is The Female Hormone Blood Test For Hair Loss?

Hormones control the hair growth cycle. Their imbalance causes the follicles to pass into the shedding stage (telogen) too early.

Free & Total Testosterone – high in PCOS, linked to androgenetic alopecia.
DHEA-S – elevated adrenal androgens cause thinning.
Prolactin – high levels can suppress estrogen, affecting hair growth.
LH & FSH – useful in PCOS and menopause evaluation.
Estrogen & Progesterone – decline during perimenopause/menopause worsens thinning.

What They Tell Us:

PCOS: High androgens + irregular menstrual bleeding.
Menopause: Low estrogen & progesterone, dry, thinning hair.
Pituitary issues: Prolactin levels that are elevated leading to shedding in the scalp.

Testing should take place between Day 2-5 of the menstrual cycle as this will produce an accurate baseline picture of your hormone levels.

Iron & Ferritin: Key Markers in Hair Fall

One of the most important blood tests that females can have when it comes to hair loss is ferritin, which is the storage form of iron. It has been found that low ferritin (< 30 ng/mL) will trigger shedding despite normal hemoglobin levels.

Normal range: 15–150 ng/mL
Optimal for hair: 70–100 ng/mL
Below 30 ng/mL: High risk of telogen effluvium

Why Women Have Low Ferritin:

Heavy menstrual bleeding
Poor iron intake (low red meat or leafy greens)
Malabsorption (celiac disease, IBS)
Pregnancy or postpartum

Ferritin Level	Hair Health Impact
<30 ng/mL	Shedding, weak strands
30–70 ng/mL	Borderline, risk of thinning
70–100 ng/mL	Optimal for growth

Treatment can be with oral or IV iron supplements, though too much iron is toxic, so supplementation should only be used under the supervision of the doctor.

CBC Test for Hair Loss: What It Tells You

A Complete Blood Count (CBC) is often the first test ordered. It evaluates general blood health and helps detect hidden anemia or systemic illness.

CBC Marker	What It Suggests
Haemoglobin	Low = anemia
Red Blood Cells	Low = poor oxygen delivery
MCV	High = B12 shortage, Low = iron shortage
White Cells	High = inflammation or infection
Platelets	High in chronic inflammation

Example:

Low hemoglobin + low MCV – iron deficiency anemia
Normal hemoglobin + low ferritin – hidden iron storage issue

The CBC test for hair loss does not confirm a diagnosis alone but directs doctors to specific nutrient or hormone tests.

Thyroid Function Tests and Female Hair Loss

The thyroid gland controls metabolism, energy and hair follicles. A slight imbalance is enough to interfere with the hair cycle. It is found that an estimated one in eight women are affected by thyroid disorders, often first showing as unexplained hair loss.

Most sensitive measure of thyroid function TSH (Thyroid Stimulating Hormone)
Free T3 (Triiodothyronine): This is an active thyroid hormone that stimulates metabolism
Free T4 (Thyroxine): The largest inactive form which is converted to T3
TPO, TG: Patients have autoimmune thyroiditis (Hashimoto or Graves)

Results:

High TSH and Low T3/T4 = Hypothyroidism ( dry, brittle hair, diffuse thinning)
Low TSH + High T3/T4 = Hyperthyroidism (fine, fragile hair, rapid shedding)
Positive antibodies = Autoimmune thyroid disease

Thyroid Condition	Effect on Hair
Hypothyroidism	Dry, coarse hair, diffuse thinning
Hyperthyroidism	Soft, fine hair, clumps of shedding
Hashimoto’s Disease	Patchy loss, slow regrowth

Vitamin Deficiency Blood Tests Related to Hair Health

The vitamins are vital during cell division, repair of follicles as well as the formation of the keratin. Dietary deficiencies amongst women are quite common due to constricted diets, absorption or heavy menstrual periods.

Vitamin D3: Deficiency is associated with alopecia areata and diffuse thinning.
Vitamin B12: Deficiency causes poor supply of oxygen to follicles.
Folate (B9): Required in DNA synthesis and in rapid muscle cell turn over.
Biotin (B7): Helps in keratin production; a lack of it leads to brittle hair and split ends.

Signs Of Deficiency:

Pale skin, fatigue (B12/folate)
Brittle nails, poor strands (biotin)
Weakness of the muscles, loss of hair (vitamin D)

Treatment:

Food (low fat meat, green vegetables with fiber, eggs, oil-rich fish)
Supplements (monitored, since an excessive amount is harmful)
Regular re-testing after 8–12 weeks

The appearance of hair is slow, so visible recovery is 3 to 6 months after fixing deficiencies.

Mineral Deficiency Blood Tests for Hair Loss

Hair growth is regulated by enzymes and hormones that are co-factored by minerals. Women with poor diets, chronic stress or absorption problems are often short of these.

Zinc: Helps repair the DNA and the growth of the follicle cells.
Selenium: Enhances anti-oxidant effect.
Magnesium: Regulates hormone balance.
Copper: Helps in forming melanin to help pigment hair.

Common Findings:

Zinc deficiency: Brittle, shedding strands (so often in illness, or in stress).
Selenium deficiency: Oxidant damage and early hair aging.
Magnesium deficiency: Worsens hormonal imbalance (PCOS, thyroid).
Copper deficiency: Loss of hair color, weak roots.

Alopecia Type	Tests Recommended
Zinc	Red meat, pumpkin seeds
Selenium	Brazil nuts, eggs, seafood
Magnesium	Spinach, nuts, whole grains
Copper	Shellfish, nuts, seeds

Does Alopecia Show Up in Blood Tests?

The word alopecia is a general term used to symbolize hair loss; however, it would be subjected to blood test findings depending on the type of alopecia. There are biochemical markers in some forms and only scalp biopsy or trichoscopy diagnoses others.

Alopecia Areata: ANA, ESR, CRP (indicators of an immune attack and inflammation)
Androgenetic Alopecia (Female Pattern): There are normal hormones, but the follicles are over-responsive to DHT.
Telogen Effluvium: This is related to acute illness, surgery or post-partum status and a lowered ferritin level.
Scarring Alopecia (Cicatricial): Never seen in blood, requires biopsy.

What Result Shows:

Alopecia areata: ANA may be positive, and so can be ESR, indicating an autoimmune cause.
Androgenetic alopecia: Hormones are normal, but the follicles are hyper responsive to DHT.
Telogen effluvium: Associated with acute illness, surgery or postpartum condition and a reduction in ferritin levels.

What If All Blood Tests Are Normal But Hair Loss Continues?

Sometimes, women have normal lab results but continue to lose hair. This does not mean the problem is “in the head”, instead, it points to non-blood-related causes.

Stress or trauma: Sometimes months after an illness, childbirth, or an emotional stress Telogen effluvium can occur.
Medications: Birth control, antidepressants, blood thinners will make you shed.
Scalp inflammation: Dandruff, Psoriasis or fungal infection attacking dermal follicles.
Undiagnosed PCOS or insulin resistance: Hormonal shifts may not appear in standard tests.
Genetics: Female pattern baldness can occur even with normal hormones.

Doctors May Recommend:

Trichoscopy (scalp magnification)
Scalp biopsy to rule out scarring alopecia
Lifestyle & stress review

A normal blood report does not mean no treatment exists, it means further evaluation is needed.

Interpreting Blood Work for Hair Loss in Females

Blood reports list a range called “normal.” But these ranges do not always match what hair needs. A woman can have “normal” ferritin but still lose hair.

Test	Normal Range	Best For Hair
Ferritin	15–150 ng/mL	70–100 ng/mL
TSH	0.5–4.5 mIU/L	0.5–2.5 mIU/L
Vitamin D	30–100 ng/mL	Above 50 ng/mL

When Should You See a Doctor?

Hair loss that does not stop on its own should not be ignored. Early treatment improves the chance of regrowth. Some types can cause permanent damage if left untreated.

See a Doctor If You Have:

Sudden shedding or bald spots
Hair falling from part line or crown
Irregular periods, acne, or weight gain
Family history of baldness
No results after months of using over-the-counter products

Can Men Also Get Hair Loss Blood Tests?

Yes, blood tests for hair loss are equally important in men. It is most commonly caused by DHT related male pattern baldness, but other contributing factors, such as thyroid dysfunction, nutrient deficiency and autoimmune disease, are also possible.

Testosterone & DHT: Detects androgenic alopecia.
Ferritin & Iron studies: Low iron can mimic female-type shedding.
Thyroid panel (TSH, T3, T4): Rules out hypo/hyperthyroidism.
Vitamin D, Zinc, B12: Deficiencies linked to chronic shedding.
CBC → Detects anemia or infections.

Hair Loss Treatment Options Based on Blood Test Results

Once doctors see the test results, they can decide the right treatment. These target the root cause, not just the scalp.

Result	Treatment
Low Ferritin	Iron supplements or food changes
High Testosterone	Spironolactone, oral contraceptives
Low Thyroid Hormone	Levothyroxine
Low Vitamin D or B12	Supplements and retesting
Autoimmune Markers	Steroids, immune therapy

It takes 3 to 6 months for hair to respond. Blood tests for hair loss in females guide the plan and track progress.

Tips to Prepare for Blood Tests for Hair Loss

The accuracy of blood tests is determined by the manner and time of testing. Time or diet-related errors can alter the outcome.

Fast 8 hours before iron or hormone tests.
Avoid vitamins 48 hours before testing.
Drink water to stay hydrated.
Test hormones between Day 2–5 of your cycle.
Tell your doctor about all medications.

Always follow lab instructions. Your doctor may repeat the test if the result looks off. This confirms the result and avoids false readings.

Additional Diagnostic Tools Besides Blood Work

Some tests need more than just blood. Doctors use other tools to check the scalp or see the hair root condition.

Scalp Biopsy: Checks for scarring alopecia.
Trichoscopy: Magnified scalp exam to see miniaturized hairs.
Hormone Scans: For PCOS or adrenal issues.
Pull Test: Counts how many hairs fall.
Hair Density Test: Measures regrowth.

See Also: Minoxidil for Females

Conclusion

Women rarely experience hair loss as a mere cosmetic problem because it is usually an indication of latent hormonal, nutritional or immunological abnormalities. Blood work like ferritin, thyroid panel, vitamin levels, and hormonal examination will help in giving an analytical guide on what to follow up on.

In cases where tests show as normal, additional examination using scalp exams or biopsy can divulge missed conditions.The main lesson: never guess tests. Knowing the internal conditions of your body saves you time, prevents useless remedies, and leads the way to focused solutions.