Iron Deficiency and Hair Loss: Does Low Ferritin Matter?

Dr Heng Jiacheng
2 hours ago
8 min read

Written by Dr Heng Jiacheng, MBBS, Diploma in Aesthetic Medicine (AAAM)Associate Member, ISHRS · Member, AAHRS. Insights from a Singapore-based hair-loss physician

Iron deficiency can be associated with diffuse, non-scarring hair shedding, even when a person’s haemoglobin level remains normal. However, not every person with low ferritin will experience hair loss, and not every case of hair loss will improve simply by taking iron.

The important first step is to determine whether iron deficiency is genuinely present, identify why it has developed and assess whether another hair-loss condition is occurring at the same time.

Can iron deficiency cause hair loss?

Yes. Iron is involved in many biological processes required by rapidly dividing cells, including cells within the hair follicle. When iron stores become depleted, some individuals may experience increased shedding, dry or fragile hair and diffuse thinning across the scalp.

Low ferritin levels have been associated with several types of hair loss, including:

Telogen effluvium
Diffuse hair shedding
Female pattern hair loss
Androgenetic alopecia occurring alongside iron deficiency

A study involving 554 non-anaemic menstruating women found that ferritin levels of 15 µg/L or below and 20 µg/L or below were significantly associated with recent hair loss.

Other studies have also found lower ferritin levels among women experiencing telogen effluvium or female pattern hair loss. evidence is not completely consistent. Some studies have not found a clear relationship between low ferritin and chronic diffuse hair loss, and there is currently insufficient evidence to recommend iron supplementation for every person presenting with hair loss.

In my clinical practice, iron deficiency is particularly relevant in premenopausal women.

Common contributing factors include:

Heavy or prolonged menstrual bleeding
Pregnancy or recent childbirth
Low intake of iron-rich foods
Vegetarian or vegan diets
Gastrointestinal conditions affecting iron absorption
Frequent blood donation

Heavy menstrual bleeding is an important cause of iron depletion and may reduce iron stores before anaemia develops. In Singapore, evaluation for heavy menstrual bleeding may include a full blood count and an iron panel to assess the extent of iron deficiency. A diet lacking of meat, poultry and seafood may also increase the risk, particularly when combined with regular menstrual blood loss.

Ferritin versus haemoglobin: what is the difference?

Haemoglobin and ferritin measure different aspects of iron status.

Haemoglobin is the oxygen-carrying protein found in red blood cells. A low haemoglobin level may indicate anaemia.

Ferritin is a protein that reflects the body’s stored iron. Ferritin can become low before haemoglobin falls, meaning a person may have depleted iron stores without yet being anaemic.

This is sometimes called iron deficiency without anaemia or non-anaemic iron deficiency.

Someone with normal haemoglobin may therefore still have low ferritin and symptoms such as fatigue, reduced exercise tolerance or increased hair shedding. In one study, low ferritin was associated with recent hair loss among women who did not have anaemia. still be interpreted in context. It can be falsely elevated during inflammation, infection and certain medical conditions. Depending on the situation, additional tests such as transferrin saturation, serum iron or inflammatory markers may be required.

What ferritin level is considered low for hair growth?

There is no universally accepted ferritin target for preventing hair loss or supporting hair regrowth.

Ferritin below 15–20 µg/L

Ferritin levels within this range generally indicate significantly depleted iron stores. Research has found an association between ferritin levels of 15 - 20 µg/L or below and recent hair loss in non-anaemic menstruating women. below 30 µg/L

One study found a strong association between ferritin levels of 30 ng/mL or below and diffuse telogen hair loss. However, observational associations do not prove that raising ferritin above this level will automatically restore hair growth. around 40 - 60 µg/L

Some hair-loss researchers and clinicians consider ferritin levels of approximately 40 - 60 µg/L more supportive of normal hair growth. A study focusing on iron-deficiency-related female alopecia proposed a ferritin level of at least 60 ng/mL, although this is not a universally adopted diagnostic or treatment threshold.

Some dermatologists and older publications have proposed aiming for ferritin levels of approximately 70 µg/L in patients with increased hair shedding. However, this target is based largely on clinical experience and observational evidence rather than robust randomised trials.

In my own clinical practice I aim for a ferritin level closer to 70 µg/L. I have observed photographic improvement in some patients as their iron stores recover. However, this remains a clinical target rather than a universally established evidence-based cutoff.

What does iron-deficiency hair loss look like?

Iron deficiency is most commonly associated with diffuse hair shedding rather than one isolated bald patch.

Iron deficiency may trigger or worsen telogen effluvium, in which a higher proportion of follicles enter the resting and shedding phase of the hair cycle.

It can also coexist with female pattern hair loss. Correcting iron deficiency may improve the nutritional environment surrounding the follicle, but it will not necessarily treat the hormonal and genetic mechanisms responsible for pattern hair loss.

Which blood tests may be considered?

Blood tests should be selected according to the individual’s history and pattern of hair loss.

Common investigations may include:

Full blood count
Serum ferritin
Transferrin saturation
Serum iron and total iron-binding capacity
Thyroid function
Vitamin D, vitamin B12 or folate when clinically indicated

Ferritin is generally more useful than a single serum iron measurement because serum iron can fluctuate throughout the day.

One thing to note is that ferritin is also an acute phase reactant, it may fluctuate when there is a recent or ongoing illness.

Finding the cause of low ferritin matters

Iron deficiency should not be treated as a laboratory number alone. The underlying reason must be identified.

In premenopausal women, heavy menstrual bleeding, pregnancy and inadequate dietary intake are common considerations.

In men and postmenopausal women, unexplained iron deficiency will require closer investigation for gastrointestinal blood loss or impaired absorption. The American Gastroenterological Association recommends gastrointestinal evaluation with upper and lower endoscopy in asymptomatic men and postmenopausal women with iron-deficiency anaemia.

Simply replacing iron without identifying an ongoing source of blood loss may delay an important diagnosis.

Heme iron versus non-heme iron

Dietary iron is available in two main forms.

Heme iron

Heme iron is found mainly in:

Red meat
Poultry
Fish
Seafood

It is generally absorbed more efficiently and is less affected by other components of a meal.

Non-heme iron

Non-heme iron is found in:

Beans and lentils
Soy products
Dark leafy vegetables
Fortified cereals
Nuts and seeds
Dried fruit

Non-heme iron can still contribute meaningfully to iron intake, but its absorption is more variable.

Vegetarian and vegan diets do not automatically cause iron deficiency. However, people following these diets may need to pay closer attention to food combinations, dietary variety and factors that affect absorption.

How to improve iron absorption from food

Vitamin C can improve the absorption of non-heme iron.

Useful combinations include:

Lentils with tomatoes or capsicum
Leafy vegetables with citrus fruit
Iron-fortified cereals with berries
Beans with vitamin C-rich vegetables
Iron supplements with vitamin C when recommended by a clinician

Tea and coffee contain polyphenols that can reduce non-heme iron absorption. Calcium may also interfere with absorption when consumed at the same time.

For someone with confirmed iron deficiency, it may be helpful to avoid taking iron supplements together with:

Tea
Coffee
Milk or calcium supplements
High-phytate meals

Current gastroenterology guidance advises taking oral iron no more than once daily. Every-other-day dosing may be better tolerated by some patients, while vitamin C may be added to improve absorption. The appropriate preparation and schedule should still be individualised.Iron supplements should not be started solely because someone is experiencing hair loss.

Excessive iron can be harmful, particularly in people with conditions that predispose them to iron overload. Supplementation can also cause:

Nausea
Abdominal discomfort
Constipation
Diarrhoea
Metallic taste
Dark stools

The evidence that iron supplementation directly improves hair growth in non-anaemic patients remains limited. Treatment decisions should therefore consider the severity of the deficiency, symptoms, ongoing blood loss and the individual’s complete clinical picture. Hair growth responds slowly because each follicle must progress through its normal growth cycle.

Even after the underlying deficiency has been corrected, visible improvement is unlikely to be immediate. In telogen effluvium, shedding may begin to settle over approximately three to six months after the trigger has been identified and addressed. More complete recovery may take around 12 months. may be longer when iron deficiency has been present for an extended period or when another condition, such as female pattern hair loss, is occurring simultaneously.

Frequently asked questions about iron deficiency and hair loss

Can low ferritin cause hair loss without anaemia?

Yes. Low ferritin has been associated with recent hair loss in menstruating women who have normal haemoglobin levels. However, low ferritin is not the only possible cause of shedding, and the association does not prove that iron supplementation alone will reverse it. itin level is best for hair growth?

There is no universally proven target. Ferritin below 15–20 µg/L generally represents clear depletion, while some hair specialists use practical targets between 40 and 70 µg/L. The higher targets are not supported by strong randomised trial evidence. I personally aim 70 ug/L.

Will taking iron regrow my hair?

Iron replacement may help when genuine iron deficiency is contributing to the shedding. It is less likely to help when iron levels are already adequate or when the main cause is genetic, hormonal, autoimmune or inflammatory.

Can iron deficiency worsen female pattern hair loss?

Iron deficiency may coexist with female pattern hair loss and could contribute to additional diffuse shedding. Correcting the deficiency may support overall follicle function, but it does not replace treatments directed at pattern hair loss.

Should everyone with hair loss test their ferritin?

Universal ferritin screening is not supported by conclusive evidence. Testing is particularly relevant when there is diffuse shedding, heavy menstrual bleeding, dietary risk, fatigue, pregnancy, recent childbirth or another reason to suspect iron deficiency.

Men and postmenopausal women with unexplained iron deficiency should seek proper medical evaluation rather than starting iron independently.

The roots² perspective

At roots², we believe that hair loss should be approached according to its underlying cause.

Iron deficiency is one possible contributor to hair shedding, but it is not the explanation for every case. Iron is included only in our Postpartum Blend, as iron deficiency is commonly encountered among patients experiencing postpartum hair loss.

For other conditions, including androgenetic alopecia and telogen effluvium, we do not routinely recommend iron supplementation unless blood testing has confirmed a deficiency. Supplementing iron without an established need may offer little benefit while exposing individuals to unnecessary side effects and the risk of excessive iron intake.

Nutritional support should complement and not replace the medical management of underlying hair-loss conditions.

References:

Iron Deficiency Anaemia. Lancet. 2016. Lopez A, Cacoub P, Macdougall IC, Peyrin-Biroulet L.Review
Iron Deficiency in Adults.The Journal of the American Medical Association. 2025. Auerbach M, DeLoughery TG, Tirnauer JS.Review
Non-Anemic Iron Deficiency: Correlations Between Symptoms and Iron Status Parameters.European Journal of Clinical Nutrition. 2022. Beatrix J, Piales C, Berland P, et al.
Micronutrients and Androgenetic Alopecia: A Systematic Review. Molecular Nutrition & Food Research. 2024. Wang R, Lin J, Liu Q, et al.
The Diagnosis and Treatment of Iron Deficiency and Its Potential Relationship to Hair Loss. Journal of the American Academy of Dermatology. 2006. Trost LB, Bergfeld WF, Calogeras E.Review
Iron Deficiency Anemia: Evaluation and Management. American Family Physician. 2025. Latimer K, Baci G, Layne M.
AGA Clinical Practice Update on Management of Iron Deficiency Anemia: Expert Review. Clinical Gastroenterology and Hepatology : The Official Clinical Practice Journal of the American Gastroenterological Association. 2024. DeLoughery TG, Jackson CS, Ko CW, Rockey DC.
AGA Clinical Practice Guidelines on the Gastrointestinal Evaluation of Iron Deficiency Anemia. Gastroenterology. 2020. Ko CW, Siddique SM, Patel A, et al.
Iron-Deficiency Anemia.The New England Journal of Medicine. 2015. Camaschella C.Review
Iron Deficiency in Infancy and Childhood.The New England Journal of Medicine. 1993. Oski FA.Review.
Micronutrients — Assessment, Requirements, Deficiencies, and Interventions. The New England Journal of Medicine. 2025. Allen LH.
The role of oral iron in the treatment of adults with iron deficiency. European Journal of Haematology. 2023. Lo JO, Benson AE, Martens KL, et al.
Nutrition-Specific Interventions for Preventing and Controlling Anaemia Throughout the Life Cycle: An Overview of Systematic Reviews. The Cochrane Database of Systematic Reviews. 2021. da Silva Lopes K, Yamaji N, Rahman MO, et al.
Psychiatric and Cognitive Outcomes of Iron Supplementation in Non-Anemic Children, Adolescents, and Menstruating Adults: A Meta-Analysis and Systematic Review. Neuroscience and Biobehavioral Reviews. 2025. Fiani D, Chahine S, Zaboube M, et al.
The Treatment of Iron Deficiency Without Anaemia (In Otherwise Healthy Persons). Swiss Medical Weekly. 2017. Clénin GE.
Non‐anaemic iron deficiency – a disease looking for recognition of diagnosis: a systematic review. European Journal of Haematology. 2016. Pratt JJ, Khan KS.
Intravenous Iron Therapy for Non-Anaemic, Iron-Deficient Adults.The Cochrane Database of Systematic Reviews. 2019. Miles LF, Litton E, Imberger G, Story D.