Can low ferritin cause hair loss?
It can, if your iron stores are low. Under 30 usually counts as low. You may see 40 or 70 quoted instead. Those numbers come from some hair researchers, not UK guidance.
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Can low ferritin cause hair loss?
Yes, it can. Ferritin is the blood test for your iron stores. The NHS lists iron deficiency as a cause of hair loss that may be temporary.
UK gut doctors (the BSG) say ferritin under 15 µg/L means no iron stores. Under 30 is generally low. Most labs set their lower limit somewhere from 15 to 30.
- Below 15 µg/LBSG: no iron stores.
- 15 to just under 30 µg/LBSG: generally low stores.
- 30 µg/L or aboveAbove the usual low line.
Source: BSG
Ferritin is like a car’s fuel gauge. A low reading says the tank is low. It doesn’t prove that’s why your hair is falling out. Ask your GP whether it needs treating.
Ferritin can also read normal when iron is low if you have an inflammatory illness. Ask your GP for ferritin and a full blood count together.
Is 40 or 70 the right ferritin for hair?
Nobody agrees. A review of the research found studies used anywhere from 15 to 70 as the line for low iron.
| Ferritin (µg/L) | What it means | Who says it |
|---|---|---|
| Under 15 | No iron stores | BSG guideline |
| Under 30 | Generally low iron stores | BSG guideline |
| Over 40 or 70 | Some authors aim for this to reverse severe shedding | Some hair researchers, with no agreement |
Sources: BSG; Almohanna 2019 review
That’s where the 40 and 70 come from. They’re some authors’ suggestions for severe shedding, not a UK guideline.
The link itself is also debated. In one study of 381 women, low iron was common, but no more common in women with pattern thinning or long-term shedding than in other women.
Five studies found no link between iron and patchy hair loss (alopecia areata). For a ferritin in the 30s, see normal vs optimal ferritin.
What does hair loss from low iron look like?
The NHS describes it as more hair coming out when brushing or washing it. Losing 50 to 100 hairs a day is normal.
Skin doctors call this kind of shedding telogen effluvium. Hair thins all over rather than in patches. A blood test may check for iron deficiency and thyroid problems.
How shedding usually runs
- 1
The trigger
Something upsets the hair cycle, such as low iron.
- 2
About 3 months later
More hair than usual starts to fall out.
- 3
3 to 6 months
The shedding phase lasts this long, then new hair grows.
- 4
Many months
Hair slowly gets back its normal thickness.
Other signs of low iron include tiredness, shortness of breath, a pounding heartbeat, paler skin and headaches. Note any you have before you see your GP.
Will iron make my hair grow back?
Maybe. One review found not enough evidence that iron changes how shedding turns out. A few controlled studies showed some benefit.
Skin doctors say medicine doesn’t speed up regrowth. But shedding can come back if low iron isn’t treated.
If your blood count is low, the NHS says iron tablets are usually taken for about 6 months. Low stores with a normal count is less clear. The BSG says treatment is reasonable if you have symptoms.
The NHS says 17mg or less a day is unlikely to harm. Take more only if your GP advises it. Higher doses can upset your stomach. Keep iron out of reach of children. An overdose in a young child can be fatal.
Never stop or change a prescribed medicine without your prescriber. If tablets aren’t working, see iron tablets not working.
How can I raise my ferritin?
Steps to raise your ferritin
- Ask your GP for ferritin and a full blood count before you buy iron.
- Eat more meat, pulses, dried fruit and dark-green leaves like kale.
- Choose breakfast cereals and bread with added iron.
- Cut down on tea, coffee and milk. Large amounts make iron harder to absorb.
- Tell your GP if your periods are heavy, a common cause of low iron.
- Retest when your GP suggests, to check your iron is rising.
Sources: NHS: iron deficiency anaemia; BSG
Still having periods? Low stores are then likely from periods or a recent pregnancy. For meal ideas, see raise ferritin with food.
Want the other bloods for thinning hair too? See hair loss blood tests.
When to speak to a GP
The NHS suggests a GP visit before paying for a hair clinic. Book an appointment if:
- You’re worried about your hair loss.
- You lose hair and feel tired, short of breath, get headaches, or notice a pounding heartbeat or paler skin. These can be signs of iron deficiency anaemia.
- Your shedding lasts more than 6 months.
- Your ferritin is low and you’re a man, past the menopause, have gut symptoms, or have a family history of gut disease. The BSG says the bar for checking your gut should be low. The NHS lists bleeding in the gut as a common cause of low iron.
New to the test? Start with the ferritin blood test guide.