How A Naturopath Uses Lab Testing to Combat Hair Loss

Medically reviewed by Dr. Pamela Frank, Toronto Naturopathic Doctor Nov 2026

Lab Testing for Hair Loss

Hair loss can be frustrating, distressing, and surprisingly difficult to figure out. For many women, it develops gradually, with increasing hair shedding, a widening part, reduced hair density, or thinning around the crown. Others experience sudden, noticeable hair loss that seems to happen almost overnight.

There are many potential contributors to hair loss, including hormonal changes, thyroid dysfunction, iron deficiency, nutritional deficiencies, genetics, insulin resistance, stress, illness, and certain medications.

One of the most important steps in addressing hair loss is understanding what may be contributing to it. This is where comprehensive laboratory testing for hair loss can be particularly helpful.

As a naturopathic doctor with more than 26 years of clinical experience and a background in medical laboratory technology, I place considerable emphasis on understanding laboratory results alongside a patient’s symptoms, medical history, diet, and hormonal health.

Rather than relying on a generic hair supplement or assuming that all hair loss is hormonal, I use targeted lab testing for hair loss to investigate potential contributing factors and develop an individualized treatment approach.

Why Does Hair Loss Happen?

Hair grows in cycles. Each hair follicle moves through three primary phases:

• Anagen: The active growth phase, which can last several years.
• Catagen: A short transitional phase during which the follicle stops growing.
• Telogen: The resting phase, after which the hair is released and eventually replaced by new growth.

Disruptions to this cycle can cause excessive shedding or gradual thinning.

Understanding the pattern of hair loss helps determine which investigations are appropriate.

1. Telogen Effluvium: Excessive Hair Shedding

Telogen effluvium is a common cause of diffuse hair shedding. It occurs when an unusually large proportion of hair follicles enter the resting phase prematurely.

Women often notice considerably more hair coming out when washing or brushing their hair. Overall hair density may decrease, although distinct bald patches are less typical.

Common triggers include:

• Significant psychological stress.
• Surgery or significant illness.
• Fever or infection.
• Childbirth and hormonal changes.
• Rapid weight loss or restrictive diets.
• Iron deficiency.
• Thyroid dysfunction.
• Certain medications.
• Nutritional deficiencies.

An important feature of telogen effluvium is its timing. Hair shedding often begins approximately two to three months after the triggering event.

A 2025 Canadian expert consensus paper recommends investigating potential triggers, including nutritional deficiencies and metabolic abnormalities, when evaluating telogen effluvium.¹

2. Female Pattern Hair Loss

Female pattern hair loss is a progressive condition characterized by gradual thinning, usually around the crown and central scalp. Women may notice that their part is becoming wider or that their ponytail is becoming less substantial.

Genetics and sensitivity of hair follicles to androgens are important factors.

Although androgens can contribute to this condition, women with female pattern hair loss can have normal circulating androgen levels.

This is an important distinction because normal testosterone results do not necessarily rule out female pattern hair loss.

A 2026 review in the Canadian Medical Association Journal emphasizes that female pattern hair loss is primarily a clinical diagnosis, with laboratory testing used selectively to investigate possible contributing conditions.²

3. Hormonal Hair Loss and PCOS

Polycystic ovary syndrome (PCOS) is an important consideration when investigating hair loss in women.

PCOS can involve elevated androgen activity, insulin resistance, irregular menstrual cycles, acne, and increased facial or body hair growth.

In some women, androgen activity contributes to progressive thinning of scalp hair.

Insulin resistance may also influence ovarian androgen production and metabolic health.

Women experiencing hair loss alongside irregular periods, acne, or increased facial hair may benefit from an investigation of androgen levels and metabolic markers.

Importantly, female pattern hair loss can occur in women without PCOS, and PCOS does not automatically mean that someone will experience scalp hair loss.

Which Lab Tests Can Help Identify the Causes of Hair Loss?

Laboratory testing should be selected according to the patient’s symptoms, examination findings, medical history, and suspected type of hair loss.

The following tests are among those I consider when ordering lab testing for hair loss.

1. Iron Studies and Ferritin

Iron deficiency is an important potential contributor to excessive hair shedding, particularly in women who menstruate.

Iron is required for many cellular processes, including those involved in rapidly dividing cells such as hair follicle cells.

Ferritin is a protein that stores iron and is commonly used to assess the body’s iron reserves.

A complete iron investigation may include:

• Ferritin: An indicator of stored iron.
• Serum iron: Measures circulating iron.
• Total iron-binding capacity (TIBC): Helps assess the blood’s capacity to bind iron.
• Transferrin saturation: Indicates the proportion of transferrin carrying iron.
• Complete blood count (CBC): Helps identify anemia and abnormalities in red blood cell indices.

Ferritin is particularly useful because iron depletion can occur before anemia develops.

A woman can have a normal hemoglobin level while still having depleted iron stores.

This is one reason why looking at a CBC alone may miss an important contributing factor.

Ferritin also increases with inflammation, so it needs to be interpreted alongside the clinical picture and other iron markers.

There is ongoing debate about the ideal ferritin concentration for hair growth. A universal hair-specific ferritin target has not been established, so results should be interpreted using the overall clinical context rather than an arbitrary number.

2. Thyroid Function Testing for Hair Loss

Thyroid hormones regulate metabolism and influence numerous tissues throughout the body, including hair follicles.

Both hypothyroidism and hyperthyroidism can contribute to changes in hair growth and excessive shedding.

Symptoms that may accompany thyroid dysfunction include:

• Fatigue.
• Changes in body temperature tolerance.
• Constipation or changes in bowel habits.
• Changes in menstrual cycles.
• Dry skin.
• Changes in weight.
• Changes in hair texture or density.

Depending on the clinical presentation, thyroid investigations may include:

• TSH (thyroid-stimulating hormone): The primary screening test for thyroid dysfunction.
• Free T4: Measures circulating unbound thyroxine.
• Free T3: May be useful in selected situations, particularly when hyperthyroidism is suspected.
• Thyroid antibodies: Such as thyroid peroxidase antibodies (TPOAb), when autoimmune thyroid disease is suspected.

An abnormal thyroid result may identify a treatable contributor to hair loss. However, thyroid dysfunction and female pattern hair loss can coexist, so addressing thyroid function may not resolve every aspect of hair thinning.

3. Androgen and Hormone Testing for Hair Loss

Hormones deserve particular attention when hair loss occurs alongside acne, irregular periods, PCOS, or other signs of androgen excess.

Androgens are hormones that include testosterone and DHEA. Although commonly associated with men, they are also important in women’s physiology.

Higher androgen activity can contribute to hair follicle miniaturization in susceptible women.

Depending on symptoms and clinical findings, hormone testing for hair loss may include:

Total testosterone and Dihydrotestosterone (DHT)

Measures the total amount of circulating testosterone, including protein-bound and unbound testosterone.

Free testosterone

Estimates the testosterone available to tissues. Accurate assessment is important because testosterone concentrations in women are relatively low.

SHBG (sex hormone-binding globulin)

SHBG is a protein that binds circulating sex hormones. Lower SHBG can increase the proportion of testosterone available to tissues.

Insulin resistance and PCOS can be associated with reduced SHBG.

DHEA-S (dehydroepiandrosterone sulfate)

DHEA-S is primarily produced by the adrenal glands. It can help investigate adrenal androgen excess.

Prolactin

Elevated prolactin can interfere with normal reproductive hormone function and menstrual cycles. Prolactin testing for hair loss is appropriate when symptoms or clinical findings suggest a possible problem.

LH and FSH

These pituitary hormones help regulate ovarian function. They may be useful in selected reproductive or endocrine investigations, although they are not routine diagnostic tests for female pattern hair loss.

Estradiol and progesterone

These hormones may be investigated when menstrual irregularities or other reproductive symptoms warrant assessment. They are not routinely required to diagnose female pattern hair loss.

An important consideration is that normal androgen concentrations do not exclude female pattern hair loss. The condition can occur because of genetic susceptibility and follicular sensitivity to androgens.

A multidisciplinary report published in the Journal of Clinical Endocrinology & Metabolism discusses the relationship between female pattern hair loss and androgen excess, including its association with PCOS.³

4. Vitamin D Testing for Hair Loss

Vitamin D has several functions beyond bone health, including roles in immune regulation and cellular signalling.

Vitamin D receptors are present in hair follicles, and vitamin D signalling is involved in normal hair follicle cycling.

Research has found associations between low vitamin D concentrations and certain hair loss conditions, particularly alopecia areata.

However, an association does not establish that vitamin D deficiency is the cause of hair loss in every individual.

A blood test measuring 25-hydroxyvitamin D can help identify vitamin D deficiency when clinically indicated.

Correcting an established deficiency is important for general health, although vitamin D supplementation should not be presented as a universal treatment for hair loss.

5. Vitamin B12 and Folate

Vitamin B12 and folate are required for DNA synthesis and normal red blood cell production.

Deficiencies can contribute to anemia and other health problems. They may also be relevant when investigating hair loss in someone with a restricted diet, digestive concerns, malabsorption, or other nutritional risk factors.

Nutrient testing for hair loss may include:

• Vitamin B12.
• Folate.
• CBC.
• Methylmalonic acid, when additional clarification of B12 status is needed.

Vitamin B12 deficiency may occur in people with inadequate dietary intake, certain gastrointestinal conditions, or impaired absorption.

Testing these nutrients can help identify deficiencies that deserve attention as part of a broader nutritional assessment.

6. Zinc

Zinc is an essential mineral involved in protein synthesis, cellular growth, immune function, and tissue repair.

It also plays a role in normal hair follicle function.

Zinc deficiency has been associated with hair loss, although supplementation has not been shown to improve hair growth consistently in people who already have adequate zinc status.

Zinc testing for hair loss may be appropriate when there are dietary restrictions, malabsorption concerns, gastrointestinal conditions, or other clinical signs suggesting deficiency.

Serum or plasma zinc can be measured, although results need to be interpreted with consideration of inflammation, recent food intake, and other factors.

7. Blood Glucose, Insulin, and Metabolic Health

Insulin resistance is particularly relevant when investigating hair loss in women with PCOS.

When the body becomes less responsive to insulin, the pancreas may compensate by producing more insulin.

Higher insulin concentrations can influence ovarian androgen production and SHBG levels, potentially contributing to increased androgen activity.

An assessment of metabolic health may include:

• Fasting glucose.
• HbA1c.
• Fasting insulin, when clinically useful.
• Lipid profile.

In women with PCOS, assessing glucose metabolism is important even when body weight is within a typical range.

Insulin resistance is not necessarily present in every woman with PCOS, and metabolic testing for hair loss should be interpreted individually.

The relationship between insulin resistance, androgen activity, and hair loss is one reason I consider the broader metabolic picture when evaluating women with PCOS and thinning hair.

8. Celiac Disease and Nutrient Malabsorption

Digestive disorders can sometimes contribute to hair loss indirectly through nutritional deficiencies and impaired nutrient absorption.

Celiac disease is an autoimmune condition triggered by gluten exposure. It can damage the small intestine and interfere with nutrient absorption.

People with celiac disease may develop iron deficiency, vitamin deficiencies, and other nutritional complications.

When symptoms or medical history suggest celiac disease, appropriate Celiac testing for hair loss may include:

• Tissue transglutaminase IgA (tTG-IgA).
• Total IgA.

Additional testing for hair loss may be required in certain circumstances.

Testing should be performed while the individual is consuming gluten, because eliminating gluten beforehand can affect test accuracy.

Routine food sensitivity panels are not an established method of identifying the cause of hair loss. Testing for a specific medical condition such as celiac disease is a more appropriate approach when the clinical history supports it.

What About Other Laboratory Testing for Hair Loss?

Depending on the history and examination, additional investigations may be appropriate.

These can include:

• Comprehensive metabolic panel.
• Liver and kidney function.
• C-reactive protein (CRP), when inflammation is suspected.
• Additional nutritional testing for hair loss when dietary intake or absorption is a concern.
• Pregnancy testing when relevant to the clinical situation.

The purpose is to investigate plausible contributing conditions while avoiding unnecessary testing for hair loss.

How Do You Put All These Test Results Together?

One of the most important aspects of investigating hair loss is understanding that laboratory results rarely tell the entire story in isolation.

For example, consider a woman who presents with gradual hair thinning, acne, irregular periods, and fatigue.

Her investigation might reveal:

• Low ferritin.
• Reduced SHBG.
• Elevated free testosterone.
• Evidence of insulin resistance.
• Normal thyroid function.

This combination of findings suggests several potential contributors that deserve attention.

Another woman might present with sudden diffuse hair shedding following a significant illness. Her thyroid function and iron status may be normal, and her history may point toward telogen effluvium.

These women have very different clinical presentations and require different approaches.

This is why I believe a thorough assessment should combine laboratory testing with a detailed health history, dietary assessment, medication review, menstrual history, and examination of the scalp and hair.

Natural Approaches to Supporting Hair Growth

Once potential contributing factors have been identified, an individualized treatment plan can be developed.

Depending on the findings, this may include the following.

1. Correcting Nutritional Deficiencies

When testing identifies a deficiency, correcting it can support normal physiological function and address a potential contributor to hair shedding.

This may involve dietary changes or targeted supplementation.

Examples include correcting iron deficiency, vitamin D deficiency, B12 deficiency, or inadequate zinc intake.

Supplementation should be based on actual needs. Excessive iron and zinc can cause adverse effects, and taking high doses of individual nutrients can create additional imbalances.

2. Improving Dietary Protein Intake

Hair is primarily composed of keratin, a protein.

Adequate dietary protein provides amino acids needed for normal hair production and tissue maintenance.

Insufficient protein intake, restrictive dieting, and rapid weight loss can contribute to telogen effluvium.

A balanced eating pattern should provide adequate protein alongside essential vitamins, minerals, and other nutrients.

3. Addressing PCOS and Insulin Resistance

For women with PCOS, improving metabolic health can be an important part of a broader treatment strategy.

This may involve:

• Eating balanced meals that support healthy blood glucose regulation.
• Including adequate protein and fibre.
• Choosing minimally processed carbohydrates.
• Engaging in regular physical activity.
• Supporting adequate sleep.
• Managing chronic stress.

These interventions can support metabolic health and may help address some of the hormonal factors associated with PCOS.

4. Supporting Thyroid Health

When thyroid dysfunction is identified, appropriate medical assessment and treatment are important.

Nutritional adequacy also matters, particularly for nutrients involved in thyroid hormone production and metabolism.

Iodine and selenium are examples of nutrients involved in thyroid function. Excessive supplementation can be harmful, so supplementation should be guided by individual requirements.

5. Managing Stress and Supporting Recovery

Significant physical and psychological stress can trigger telogen effluvium.

Adequate sleep, recovery, balanced nutrition, and appropriate stress management can support general health and recovery of the normal hair growth cycle.

When a temporary trigger has resolved, hair shedding often improves over subsequent months. Visible restoration of hair density takes longer because hair grows slowly.

6. Considering Evidence-Based Hair Loss Treatments

Nutritional and lifestyle interventions are valuable when underlying deficiencies or metabolic contributors are present.

Some forms of hair loss also require specific dermatological treatment.

Topical minoxidil is an established treatment option for female pattern hair loss. Other medical treatments may be considered depending on the diagnosis, reproductive status, contraindications, and individual circumstances.

A 2025 Canadian consensus on androgenetic alopecia reviewed available interventions and identified topical minoxidil among its recommended treatments.⁴

A collaborative approach involving a naturopathic doctor, family physician, endocrinologist, or dermatologist may be appropriate.

When Should You Seek Further Medical Assessment?

Some forms of hair loss warrant prompt assessment by a physician or dermatologist.

These include:

• Rapidly progressing hair loss.
• Distinct bald patches.
• Scalp redness, scaling, pain, burning, or inflammation.
• Loss of eyebrow or eyelash hair.
• Signs of scarring or permanent follicular damage.
• Sudden development of significant androgen-related symptoms, such as rapidly progressing facial hair growth or voice changes.

Early assessment is important when scarring alopecia or another underlying medical condition is suspected.

Investigating Hair Loss with a Comprehensive Approach

Hair loss is often multifactorial. Iron deficiency, thyroid dysfunction, hormonal changes, PCOS, insulin resistance, nutritional deficiencies, and genetic susceptibility can all play a role.

Finding the relevant contributors requires more than simply ordering a large panel of blood tests. It requires understanding which tests are appropriate, how the results relate to one another, and how they fit with the patient’s symptoms and clinical history.

My background in medical laboratory technology, combined with more than 26 years of naturopathic clinical experience, has shaped my approach to investigating complex health concerns.

I use laboratory testing, nutritional assessment, and a detailed review of hormonal and metabolic health to help identify potential contributors to hair loss and develop an individualized plan.

If you are experiencing thinning hair, excessive shedding, or changes in hair density, investigating the underlying factors is a useful place to start.

Book an appointment with Dr. Pamela Frank, Naturopathic Doctor in Toronto, to discuss a comprehensive approach to investigating hair loss.

Dr. Pamela Frank, BSc(Hons), ND
Naturopathic Doctor in Toronto
In practice since 1999
www.naturopathtoronto.ca

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References

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2. McMullen E, Saed Aldien A, Sibbald C, Donovan J. Female pattern hair loss. CMAJ. 2026;198(8). doi:10.1503/cmaj.251058
3. Carmina E, Azziz R, Bergfeld W, et al. Female Pattern Hair Loss and Androgen Excess: A Report From the Multidisciplinary Androgen Excess and PCOS Committee. J Clin Endocrinol Metab. 2019;104(7):2875-2891. doi:10.1210/jc.2018-02548
4. Landells I, Chow E, Gupta AK, et al. A Canadian Consensus on Androgenetic Alopecia: Approach and Management. J Cutan Med Surg. 2025;29(5 suppl):5-14. doi:10.1177/12034754251368849
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Medical disclaimer: This article is intended for educational purposes and does not replace individualized medical assessment, diagnosis, or treatment. Laboratory testing and treatment recommendations should be determined by a qualified healthcare professional based on individual circumstances.

By Dr. Pamela Frank, BSc(Hons), ND