A ferritin of around 45 ng/mL usually sits inside the "normal" range on a standard lab report — but for hair fall specifically, many doctors use a higher threshold than the one used to diagnose anaemia. That gap is why you can be told your iron "looks fine" on a general report, while a ferritin level in that same range is still considered a reasonable contributor to ongoing hair shedding.

Why hair fall uses a different ferritin bar than anaemia does

  • The standard lab "normal" range for ferritin is wide — often roughly 15-150 ng/mL (ranges vary by lab) — and is set mainly to flag the kind of deficiency that causes anaemia
  • Hair follicles are more sensitive to borderline-low iron stores than red blood cell production is. A ferritin level that's technically "normal" for anaemia purposes can still be low enough to affect hair growth, since hair follicles are a non-essential tissue your body deprioritises early when iron stores run tighter
  • Many dermatologists and trichologists treat for hair fall at a ferritin level higher than the anaemia cutoff — commonly somewhere in the 40-70 ng/mL range is considered a reasonable target rather than just "above the lab's lower limit" — though the exact number your doctor uses can vary, and this is a judgement call, not a fixed rule
  • This is why two different doctors can look at the same "45" and give different advice — one reading it purely against the anaemia range, another treating it as a contributing factor to hair fall specifically

What else matters alongside the number

Ferritin alone doesn't explain all hair fall, and treating it in isolation when another cause is driving the shedding won't fully fix it. Worth ruling out or discussing alongside a borderline ferritin:

  • Thyroid function — both an underactive and overactive thyroid can cause hair thinning
  • Recent major stress, illness, surgery, delivery, or rapid weight change — these can trigger a temporary shedding phase (telogen effluvium) independent of iron
  • PCOS or other hormonal causes, which can cause a different pattern of thinning
  • How long the hair fall has been going on, and whether it's diffuse (all over) or patchy, since patchy hair loss points toward different causes entirely

What treating it usually looks like

  • Oral iron supplementation, at a dose and duration your doctor sets based on your ferritin level, diet, and whether you have any ongoing iron losses (such as heavy periods)
  • Dietary iron sources alongside supplementation — but diet alone rarely corrects an existing deficiency fast enough on its own
  • A repeat ferritin check after a few months to confirm the level has actually moved, since hair regrowth itself takes months to become visible even once the underlying level improves
  • Patience with the timeline — even once ferritin is corrected, visible improvement in hair fall typically takes several months, since hair growth cycles are slow

A ferritin inside the general "normal" range doesn't automatically rule out iron as a contributor to your hair fall — it depends on where in that range you sit and what else is going on.

Frequently asked

If my ferritin is 45 and my haemoglobin is normal, am I iron deficient?

Not in the sense that causes anaemia — but for hair fall specifically, a ferritin of 45 can still be treated as worth correcting, depending on your doctor's judgement and whether other causes have been ruled out. This is a different question from whether you have iron-deficiency anaemia; our guide on low ferritin with normal haemoglobin covers that distinction in more depth.

How long before I see less hair fall after starting iron?

Hair growth cycles are slow, so most people don't notice a meaningful change for at least two to three months after starting treatment, even once ferritin levels improve. Shedding you see today reflects follicles that were affected weeks to months ago.

Should I just start an iron supplement on my own since my ferritin is on the lower side?

It's better to have your doctor confirm the dose and duration based on your actual level and any other findings, rather than self-dosing — unnecessary or excessive iron supplementation isn't harmless, and the underlying cause (if it isn't iron) won't be addressed by guessing.

Does my hair fall keep coming back because the ferritin keeps dropping again?

It can — if there's an ongoing cause of iron loss (commonly heavy periods) or poor absorption, ferritin can fall again after treatment. Our guide on iron deficiency that keeps coming back goes into the specific reasons that happens.