Iron Deficiency, Anaemia and Hair Loss
Last reviewed on 2 August 2026. We review our treatment guides every six months to keep them accurate.
Iron deficiency, and the anaemia it can lead to, is one of the more common nutritional reasons for hair loss, and it is usually reversible once your iron levels are put right. Iron deficiency anaemia, spelled anemia in the US, means your body does not have enough iron to make healthy red blood cells, and running low on iron can also show up as increased hair shedding. This guide explains how low iron affects the hair, how it is checked with a ferritin blood test, roughly how long recovery takes, and why you should always test before you supplement. It is general information rather than medical advice, so please speak to your GP about your own hair loss. For a reliable overview, the NHS guide to iron deficiency anaemia is a good place to start.
Does iron deficiency cause hair loss?
In short, low iron is a recognised cause of hair loss. The NHS lists hair loss among the symptoms of iron deficiency anaemia, describing it as noticing more hair coming out when you brush or wash it, and the American Academy of Dermatology includes too little iron among the nutritional causes of noticeable hair loss, adding that hair can regrow once the body gets enough of the missing nutrient.
It is worth being honest about where the evidence is less settled. Whether low iron on its own, without full anaemia, is enough to cause hair loss is genuinely debated. A widely cited review of diet and hair loss concluded that it is still unknown whether a shortage of stored iron contributes to hair loss, because studies have reached conflicting results. What is not in doubt is that correcting a genuine deficiency is good for your health, and that where low iron is driving shedding, restoring your levels can allow the hair to recover.
Iron deficiency with and without anaemia
Iron deficiency and anaemia are related but not the same thing. Your body keeps a store of iron, and the level of a protein called ferritin reflects how full that store is. As the store runs down, ferritin falls first. Anaemia, where there are too few healthy red blood cells to carry oxygen around the body, is what can follow when iron drops far enough. This means you can be low in iron, with a low ferritin, before you ever become anaemic, which is why a doctor looks at ferritin as well as a standard blood count when hair loss is a concern.
How low iron leads to hair shedding
When iron runs low it usually causes diffuse shedding, a telogen effluvium that pushes more follicles into the resting phase, and it is generally temporary.
Hair follicles are among the most active tissues in the body, so they are sensitive to shortfalls in the raw materials they need. When iron runs low, the shedding it causes is usually diffuse, meaning the hair shows even thinning across the whole scalp rather than distinct bald patches. This pattern is typical of a condition called telogen effluvium, in which a trigger such as low iron, illness or stress pushes more follicles than usual into their resting and shedding phase. Because the follicles themselves are not damaged, this kind of hair loss is generally temporary, and DermNet lists correcting iron levels among the steps that help it settle.
Who is most at risk of low iron
Iron deficiency is common, and some groups are more prone to it than others:
- Women who menstruate, particularly with heavy periods, and women who are pregnant, which the NHS describes as very common causes of iron deficiency anaemia.
- Vegetarians and vegans, because the iron in plant foods is less easily absorbed, so more is needed from the diet.
- Anyone losing blood from the stomach or gut, for example from ulcers or long-term use of some anti-inflammatory painkillers, which a doctor may want to investigate.
- People with conditions that reduce how well iron is absorbed from food.
Symptoms of iron deficiency
Hair loss is rarely the only sign, and it is usually not the first. The NHS lists common symptoms of iron deficiency anaemia as:
- tiredness and a lack of energy
- shortness of breath
- skin that is paler than usual
- hair loss, noticed as more hair coming out when brushing or washing it
Because these overlap with many other conditions, the reliable way to know whether low iron is part of your picture is a blood test rather than a symptom checklist.
Getting tested: the ferritin blood test
If iron might be behind your hair loss, your GP can arrange a blood test. This usually includes a full blood count and a ferritin level, which shows how much iron your body has in store. A low ferritin points to depleted iron stores. Some dermatologists prefer to see ferritin comfortably within range rather than just above the very bottom when hair loss is a concern, and the review of diet and hair loss notes targets such as a ferritin above around 50 micrograms per litre, though this is a clinical judgement for your doctor to make. One caveat is that ferritin can rise temporarily during illness or inflammation, so a normal reading does not always rule out low iron. Interpreting the result, and deciding what to do about it, is a job for your GP rather than for self-diagnosis.
Treatment and recovery
Treatment is aimed at the deficiency, not at the hair directly. Where a blood test confirms low iron, the NHS says iron tablets are usually recommended to replace what is missing, and are typically taken for about six months so the stores refill, not just until symptoms ease. Just as important is finding and treating the cause, whether that is heavy periods, blood loss from the gut, or a diet low in iron, so the deficiency does not simply return.
Because the hair grows on a slow cycle, regrowth follows correction gradually. Once your iron stores are restored, shedding tends to settle and the hair thickens back up over several months, and it can take six months or more to feel noticeably fuller. It is not instant, and it is not guaranteed if something else is also contributing, but for hair loss driven by low iron the outlook is generally good.
Iron-rich foods
A balanced diet with enough iron supports healthy stores. The NHS lists good sources including:
- lean red meat and liver (although liver should be avoided in pregnancy)
- beans, peas and lentils
- dark-green leafy vegetables such as kale and watercress
- nuts and dried fruit such as apricots, prunes and raisins
- fortified breakfast cereals
A drink of orange juice with a meal can help your body absorb iron from plant foods, which is useful if you are vegetarian or vegan.
Recommended daily iron
The NHS recommends adult men have 8.7mg of iron a day, women aged 19 to 49 have 14.8mg a day, and women aged 50 and over have 8.7mg a day. Most people can get all the iron they need from a varied diet.
Why you should test before you supplement
It is tempting to reach for an iron supplement at the first sign of shedding, but iron is one to be careful with. Unlike some nutrients, the body has no easy way to get rid of a surplus, so extra iron builds up and too much is harmful. The NHS notes that high doses, over 20mg a day, can cause side effects such as constipation, feeling or being sick and stomach pain, while 17mg or less a day is unlikely to cause harm. Rarely, in a genetic condition called haemochromatosis, the body stores too much iron and can be damaged over time. Taking iron you do not need offers no benefit for your hair and carries a real downside, which is exactly why testing first matters. If you do keep iron tablets at home, keep them well out of reach of children, as the NHS warns that an iron overdose in a young child can be fatal.
When to see a doctor
See your GP if you are worried about hair loss, if it is sudden or heavy, or if you have other symptoms such as tiredness, breathlessness or unusually pale skin. A simple blood test can show whether low iron is involved, and your GP can look for the underlying cause. Working out what is behind your hair loss with a doctor first is sensible before considering any commercial hair clinic, since the right approach depends entirely on the diagnosis.
Frequently asked questions
Can iron deficiency or anaemia cause permanent hair loss?
It usually does not. Hair loss linked to low iron is generally a temporary, diffuse shedding, and because the follicles are not damaged, the hair tends to grow back once your iron stores are restored. If shedding carries on after your iron is corrected, it is worth seeing your GP to check for another cause.
How long does it take for hair to recover after treating anaemia?
Hair grows on a slow cycle, so regrowth is gradual. Once iron levels are restored, shedding usually settles and the hair thickens back up over several months, and it can take six months or more to look noticeably fuller. There is no single timeline that fits everyone.
Can low iron cause hair loss without anaemia?
This is genuinely debated. You can have low iron stores, shown by a low ferritin, before becoming anaemic, and some people shed at this stage. Research has reached conflicting results on whether low stored iron alone causes hair loss, so it is best assessed by your GP alongside your other symptoms.
How can I increase my iron through diet?
Include iron-rich foods such as lean red meat, beans, lentils, dark-green leafy vegetables, nuts, dried fruit and fortified cereals. If you are vegetarian or vegan, having a source of vitamin C, such as orange juice, with meals helps your body absorb iron from plant foods.
Is it safe to take iron supplements without a doctor's advice?
It is better to test first. The body cannot easily get rid of excess iron, so taking it when you do not need it can build up and cause harm. A blood test tells you whether you are actually low before you supplement, so speak to your GP rather than starting iron on your own.
Does anaemia cause hair loss in women more than men?
Iron deficiency is more common in women, largely because of blood loss from periods and the demands of pregnancy, so anaemia-related shedding is seen more often in women. That said, men and postmenopausal women can also become iron deficient, often from blood loss in the gut, which a doctor may want to investigate.
The bottom line
Iron deficiency, with or without anaemia, is a recognised and common cause of hair loss, usually as a diffuse shedding across the whole scalp, and it is generally reversible once your iron is restored. Whether low iron on its own is enough to cause shedding is still debated, but a genuine deficiency is always worth correcting. The sensible route is to ask your GP for a blood test that includes ferritin, treat any deficiency and its underlying cause, eat a diet with enough iron, and be patient while the hair recovers over several months. Above all, test before you supplement, because too much iron is harmful and there is no easy way for the body to remove it.
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