Low Ferritin and Hair Loss. The Iron Level Your Hair Needs, Why a Normal Result Can Still Be Too Low and How to Correct It
Ferritin is the protein that stores iron, and a blood ferritin level is the most reliable simple measure of how much iron your body has in reserve. Low iron stores are one of the commonest correctable findings in people who are shedding hair, particularly women. The research on exactly how strongly iron and hair loss are linked is mixed, but the practical message is consistent. If you are shedding, your ferritin should be measured, interpreted properly and corrected if it is low, before or alongside any hair treatment.
Key points
Ferritin reflects iron stores. NICE states that a ferritin below 30 micrograms per litre confirms iron deficiency, even when haemoglobin is normal.
Laboratory reference ranges often start well below 30, so a result flagged as normal can still indicate depleted stores.
Ferritin rises with inflammation, infection and liver conditions, which can hide iron deficiency. The WHO uses a higher cut-off of 70 in adults with inflammation.
Correcting low iron takes months, not weeks, and hair regrowth follows the iron, often with a delay of 3 months or more.
Shedding and unsure what your bloods mean? Message a GMC-registered doctor on WhatsApp or email team@thewellnesslondon.com.
What is ferritin and why does it matter for hair?
Iron is carried in the blood by haemoglobin and stored in the body bound to ferritin. When intake falls short of losses, the stores run down first and haemoglobin falls last. That means a person can be iron deficient for months, with a completely normal full blood count, before anaemia appears.
Hair follicles are among the most active tissues in the body, and hair growth is not essential for survival. When resources are short, growth is one of the first things to slow. Iron deficiency is associated in many studies with telogen effluvium, a diffuse shed in which more hairs than usual move into the resting phase and fall out, and it is common in women with female pattern thinning.
Is the evidence clear?
Not entirely, and it is worth being honest about this. A 2022 systematic review in Skin Appendage Disorders concluded there is no clear-cut evidence of an association between iron deficiency and non-scarring hair loss in women, while other studies have found lower ferritin levels in people with shedding than in those without. Part of the difficulty is that iron deficiency is common in the general population, particularly in menstruating women, so it appears often in both groups.
What is not disputed is that iron deficiency causes fatigue, poor concentration and reduced exercise tolerance, and should be treated for its own sake. Correcting it removes one possible cause of shedding, costs little and carries little risk when done properly.
What ferritin level is too low?
NICE Clinical Knowledge Summaries state that in all people a ferritin below 30 micrograms per litre confirms iron deficiency. The World Health Organization uses 15 micrograms per litre as its threshold in otherwise healthy adults, and 70 in adults with infection or inflammation, because ferritin rises in those states and can mask low stores.
Many laboratory reference ranges begin at values well below 30. A result of 18 or 22 may therefore be reported without a flag while meeting the NICE definition of iron deficiency. This is one of the commonest reasons people with shedding are told their bloods are fine.
No trial has set a specific ferritin target for hair regrowth. Many hair specialists aim comfortably above the deficiency range before judging whether a hair treatment is working, and interpret the result alongside the full blood count, iron studies, C-reactive protein, thyroid function and vitamin D.
Want your results read properly? Ask our doctors on WhatsApp.
Why is my ferritin low?
In women of reproductive age, heavy periods are the commonest cause. Other causes include pregnancy and breastfeeding, a diet low in iron such as some vegetarian and vegan diets, frequent blood donation, intense endurance training, and coeliac disease, which reduces absorption. Weight-loss surgery and long-term use of acid-suppressing medicines can also reduce absorption.
In men and in women after the menopause, iron deficiency without an obvious cause needs investigating, because hidden blood loss from the gut must be excluded. This is a medical question, not a hair question, and it is one reason a doctor should review your results.
How do you correct low ferritin?
Oral iron is the usual first step. Taking it once daily or on alternate days is often better tolerated and may be absorbed as well as more frequent dosing. Taking it with a source of vitamin C, and away from tea, coffee, calcium and antacids, improves absorption. Treatment typically continues for around 3 months after levels have normalised, to refill stores rather than simply reach the bottom of the range.
Where oral iron is not tolerated, not absorbed or not working, intravenous iron restores stores quickly. Ferritin should be rechecked to confirm the correction, because iron supplements taken without monitoring can overshoot, and too much iron is harmful.
Hair responds slowly. Because follicles that have entered the resting phase take months to cycle back into growth, visible improvement usually lags the blood result by 3 months or more.
Where does PRP fit?
If iron deficiency is the only cause of a diffuse shed, correcting it may be all that is needed. Many people, however, have more than one thing going on, most often pattern thinning that the shed has made more visible. Treating the iron deficiency alone will not reverse pattern thinning.
That is where treatment such as PRP comes in. PRP uses growth factors concentrated from your own blood, has no hormonal action, and meta-analyses of randomised trials have found it increases hair density in pattern hair loss. It works best on a scalp that is not also short of iron, which is why bloods come first here. Our guide on whether PRP for hair is worth it covers the evidence in detail.
The suitability review
Every enquiry begins with a doctor-led suitability review rather than a booking. A GMC-registered doctor examines your scalp with dermoscopy, reviews or arranges your bloods, and tells you plainly whether PRP is right for you now, later or not at all. Correcting a low ferritin first is a common recommendation.
What assessment and treatment cost
At The London PRP Clinic by The Wellness, the price reflects a doctor-led, blood-test-first approach rather than a treatment sold at the door.
Core Wellness blood panel of 30 markers including ferritin, full blood count, thyroid, inflammation and vitamin D, doctor-reviewed with a written plan, £350.
Advanced Health panel of 55 markers including full iron studies and full thyroid function, with a priority GP results call, £650.
Hair PRP, £450 per session, or £1,215 for a course of 3 sessions.
Book your suitability review. Message us on WhatsApp.
Why people choose The London PRP Clinic by The Wellness
Because bloods are interpreted against clinical definitions of deficiency, not just the laboratory's printed range.
Because the cause of low iron is looked for, not simply topped up.
Because PRP is recommended only when the scalp and the bloods say it will help, and many people are advised to correct their iron first.
And because every treatment is delivered by GMC-registered doctors at 10 Portman Square in Marylebone and the Light Centre in Belgravia.
Related reading
Our guides to hair loss in London and the blood tests that matter, telogen effluvium and thyroid and hair loss explain the other causes worth checking.
Book your suitability review. Message us on WhatsApp, email team@thewellnesslondon.com, or call +44 20 3951 3429.
Frequently asked questions about ferritin and hair loss
Can low ferritin cause hair loss?
Low iron stores are associated with diffuse shedding in many studies, although the evidence is mixed. Correcting a low ferritin removes one possible cause and treats the fatigue that often comes with it.
What ferritin level is too low?
NICE states that a ferritin below 30 micrograms per litre confirms iron deficiency. The WHO uses 15 in healthy adults and 70 in adults with inflammation, because inflammation raises ferritin.
My ferritin was normal. Could it still be too low?
Yes. Many laboratory ranges begin below 30, so a result flagged as normal can still meet the NICE definition of iron deficiency.
How long does it take for hair to grow back after correcting iron?
Visible improvement usually lags the blood result by 3 months or more, because resting follicles take time to return to growth.
Should I take iron supplements without a blood test?
No. Iron should be taken for a confirmed deficiency and monitored, because too much iron is harmful and unexplained deficiency needs investigating.
Does PRP work if my ferritin is low?
PRP works best when iron deficiency has been corrected. Many people are advised to correct their ferritin first and consider PRP if pattern thinning remains.
This article is for information and does not replace personal medical advice. Do not start iron supplements without a confirmed deficiency. Individual results vary. All treatments at The London PRP Clinic by The Wellness are performed by GMC-registered doctors. Written and reviewed by the clinical team at The Wellness. Last updated September 2026.