Low Ferritin and Hair Loss: The Hidden Reason Your Hair Isn't Growing

Natalie Harrison
Low Ferritin and Hair Loss: The Hidden Reason Your Hair Isn't Growing

There is a particular kind of frustration that comes from doing everything right - eating well, sleeping more, reducing stress, maybe even trying a supplement - and still watching your hair come out in the brush every morning. If that is where you are, this is worth reading.

Most standard blood panels check your iron. But there is a closely related number that often goes untested, a number called ferritin, and it might be the explanation your hair has been waiting for. Low ferritin and hair loss have a well-documented connection in the research, and yet many people are told their results are "normal" without ever knowing that normal is not the same as optimal for hair.

The reassuring thing is that this is a known, explainable, and addressable cause. Understanding it can genuinely change the direction of your hair journey.

What Is Ferritin and What Does It Have to Do with Your Hair?

Iron and ferritin are not the same thing. Serum iron is the iron circulating in your bloodstream right now. Ferritin is your stored iron, the reserve your body draws on when circulating supplies run low.

Think of serum iron as the cash in your wallet and ferritin as your savings account. You can have a passable amount of cash right now while your savings are critically depleted, and it is the savings your body will raid first when it needs resources for something important.

Hair follicles are among the most metabolically active structures in the body. They rely heavily on adequate iron stores to fuel the rapid cell division that drives hair growth. Here is what happens when ferritin drops:

  • The body reprioritises. When iron stores fall, the body redirects resources to vital organs and functions, and hair growth, classified as non-essential, is one of the first things to slow or pause

  • Follicles are literally depleted. Hair follicles contain their own ferritin stores, and the body pulls from them when overall reserves drop, directly reducing the follicle's ability to produce strong, healthy strands

  • Telogen effluvium is triggered. This is the medical term for the type of diffuse, all-over shedding that low ferritin commonly causes - more hairs entering the resting phase at the same time, then shedding together weeks later

  • Strands become thinner and weaker. Even before noticeable shedding begins, hair may become finer in texture, more prone to breakage, and slower to grow back after cutting

  • A 2025 peer-reviewed study published in PMC found that women with hair loss had significantly lower mean ferritin levels (39.34 ng/mL) compared to healthy controls (48.09 ng/mL), reinforcing ferritin as a measurable biomarker of hair health

The "Normal" vs "Optimal" Problem

This is where a lot of people fall through the cracks. Standard laboratory "normal" ranges for ferritin can start as low as 12 to 15 ng/mL in many clinics. Research focused on hair health, however, consistently points to a much higher optimal threshold.

Hair loss specialists and trichologists typically cite optimal ferritin for healthy hair growth as 40 to 70 ng/mL, with some research suggesting levels should ideally be above 40 ng/mL to avoid triggering excess shedding.

If your ferritin result sits at, say, 18 ng/mL and your clinic's normal range starts at 12, you may have been told your result was fine. But your hair follicles may be experiencing real deprivation at that level. Knowing the actual number, not just the pass or fail, is everything.

Common Mistakes That Can Make Things Worse

When hair is falling out and answers feel elusive, the instinct is to act quickly. That is completely understandable. But a few well-meaning responses can quietly delay recovery.

  • Testing iron but not ferritin, or not asking for the actual number. The most common missed step is accepting a general "your bloods look fine" without knowing the specific ferritin reading. Standard panels do not always include ferritin unless you request it, and even then, knowing the number matters more than the pass/fail.

  • Over-supplementing iron without confirmed deficiency. Iron is one of the few nutrients where supplementing above your needs can cause genuine harm. Too much iron is toxic; supplementing without confirmed low ferritin and proper medical guidance is not the solution.

  • Drinking tea or coffee with meals. Tannins in both drinks bind to dietary iron and block its absorption significantly. Even a cup of tea 30 minutes before or after an iron-rich meal can reduce absorption by up to 60 to 80 percent.

  • Relying entirely on plant-based iron sources without optimising absorption. Non-haem iron from plants is harder to absorb than haem iron from animal sources. Without pairing plant-based iron with Vitamin C and separating it from absorption blockers, even a good diet may not be enough.

  • Expecting fast results. Even when ferritin levels are corrected, hair regrowth follows the biological growth cycle, which means visible improvement typically takes 3 to 6 months. The temptation to stop supplements or change course at the 4-week mark is one of the most common reasons people miss the recovery that was already underway.

Practical Steps That Genuinely Help

These steps are useful regardless of whether you have confirmed low ferritin, and regardless of whether you ever use Kiri10.

1. Ask for the ferritin number specifically.
When booking a blood test with your GP or naturopath, ask for serum ferritin alongside full blood count and haemoglobin. Then ask for the actual number, not just whether it is "in range." Anything below 40 ng/mL is worth discussing in the context of hair health, even if the lab marks it as normal.

2. Increase dietary iron in ways that actually absorb.
Red meat, dark leafy greens (spinach, silverbeet, kale), lentils, pumpkin seeds, and eggs are all excellent sources. The key is pairing them with Vitamin C, which significantly enhances non-haem iron absorption. A squeeze of lemon over spinach, or an orange alongside a lentil dish, makes a real difference.

3. Time your iron-blockers separately.
If you drink tea, coffee, or consume a lot of dairy, try to separate these from iron-rich meals by at least an hour. Calcium and tannins both inhibit iron absorption, and many people are unknowingly counteracting their dietary efforts at every meal.

4. Check your Vitamin D too.
Vitamin D and ferritin are frequently co-deficient in people with hair shedding, particularly in NZ/AU winter when sun exposure drops. A 2020 PMC study found that ferritin and Vitamin D levels were generally low in patients presenting with hair loss, suggesting they are worth checking together.

5. Be patient, and measure progress differently.
Rather than counting hairs in the shower, take a monthly photo in the same lighting at the same spot. Hair recovery from ferritin correction is gradual, and the changes are subtle in the early months before becoming obvious. Consistent documentation is the most reliable way to track real progress.

6. Support absorption from the gut up.
If gut health is compromised through conditions like IBS, coeliac disease, or chronic inflammation, iron absorption can be poor regardless of how much you eat or supplement. Supporting gut health is supporting iron status. If this applies to you, our blog on the gut-hair connection goes deeper on this.

7. Consider whether perimenopause is a factor.
As oestrogen declines during the perimenopausal transition, the body's ability to absorb and retain iron can reduce. If you are experiencing other hormonal changes alongside hair shedding, ferritin is one of the most important numbers to check. Our blog on perimenopause and autumn shedding covers this crossover in detail.

Where Kiri10 Fits In

KiriGlow™ does not contain iron, and that is worth saying clearly. Iron supplementation needs to be based on confirmed test results and medical guidance, and there is no one-size-fits-all dose that is safe to self-prescribe.

What KiriGlow™ does deliver, as part of our Triple-Keratin Complex, is Functional Keratin™, Zinc, Copper, OptiMSM™, Marine Collagen, and Biotin. These work on the structural and enzymatic side of hair health, and zinc and copper in particular play an important role in the enzyme systems that support iron metabolism and keratin synthesis at the follicle level.

Functional Keratin™ is the hero of that formulation. Sourced from New Zealand sheep wool and processed at low temperature to preserve its intact bioactive structure, it is 91% bio-identical to the keratin in human hair. Unlike hydrolysed keratin, which is fragmented through harsh acid processing into pieces too small to function as a protein, Functional Keratin™ retains its biological activity. It was clinically studied to reduce shedding by up to 43% in trials.

The inside-out philosophy here matters especially when ferritin is a factor. While dietary changes and medical guidance address the iron storage side, KiriGlow™ keratin capsules and the Glow and Protect Bundle directly nourish the follicle system with the building blocks hair is made of. KiriCare™ shampoo, conditioner, and serum work on the outside to protect the strands that are growing, reduce breakage, and support a healthy scalp environment throughout the recovery window.

Results take 3 to 6 months of consistent daily use. That is not a limitation, it is just biology. The work done now is what you will see in your hair in spring. 🧡

For a full picture of your inside-out hair wellness routine, download the free Kiri10 Hair Wellness Guide.

References

  1. Trüeb RM. Serum Biotin Levels in Women Complaining of Hair Loss. International Journal of Trichology. General reference, PMC. https://pmc.ncbi.nlm.nih.gov/articles/PMC5582478/

  2. Cheung EJ, et al. Assessment of Serum Ferritin Levels in Female Patients with Telogen Effluvium. PMC / NIH. 2025 Dec. https://pmc.ncbi.nlm.nih.gov/articles/PMC12839778/

  3. Guo EL, Katta R. Diet and hair loss: effects of nutrient deficiency and supplement use. Dermatology Practical and Conceptual. 2017. https://pmc.ncbi.nlm.nih.gov/articles/PMC5315033/

  4. Cheung EJ, et al. Quantitative Analysis of Selected Circulating Hematological Parameters in Female Hair Loss. PMC / NIH. 2025. https://pmc.ncbi.nlm.nih.gov/articles/PMC12651287/

  5. Özdemir FT, et al. Serum ferritin and vitamin D levels should be evaluated in patients complaining of hair loss. PMC / NIH. 2020. https://pmc.ncbi.nlm.nih.gov/articles/PMC7394174/

  6. GoodRx Health (medically reviewed). Can Iron Deficiency Cause Hair Loss? 2023. https://www.goodrx.com/conditions/hair-loss/can-iron-deficiency-cause-hair-loss

  7. StatPearls. Telogen Effluvium. National Institutes of Health / NCBI Bookshelf. Updated 2024. https://www.ncbi.nlm.nih.gov/books/NBK430848/

  8. Almohanna HM, et al. The Role of Vitamins and Minerals in Hair Loss: A Review. Dermatology and Therapy. 2019. PMC. https://pmc.ncbi.nlm.nih.gov/articles/PMC6380979/

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FAQ's

  • What ferritin level causes hair loss?

    Research suggests that ferritin below 30 to 40 ng/mL can trigger excess hair shedding, even when haemoglobin and serum iron appear normal. Hair loss specialists typically recommend ferritin above 40 to 70 ng/mL for optimal hair growth. The standard lab normal range can start as low as 12 to 15 ng/mL, meaning many people with thinning hair are told their results are fine despite being below the threshold their follicles actually need.

  • Can my ferritin be low even if my iron levels are normal?

    Yes, and this is one of the most common sources of confusion. Serum iron (the iron circulating in your blood) and ferritin (your stored iron protein) are different measurements. It is entirely possible to have serum iron within range while ferritin is significantly depleted, and it is the ferritin level that hair follicles draw on for fuel

  • How long does hair take to grow back after correcting low ferritin?

    Even after iron stores are restored, hair regrowth follows the biological hair cycle, meaning visible improvement in density typically takes 3 to 6 months. The follicles need time to move back through the growth cycle and produce new strands long enough to see. Consistent support and patience are both essential parts of the recovery process.

  • What are the signs that low ferritin is causing hair loss?

    Low ferritin hair loss typically presents as diffuse, all-over shedding rather than patchy loss, hair that feels finer and more fragile, and a parting that looks wider than it used to. It is often accompanied by fatigue, pale skin, and feeling cold easily. A blood test for serum ferritin is the only way to confirm the connection.

  • Does KiriGlow™ help with low ferritin hair loss?

    KiriGlow™ does not contain iron and is not a treatment for iron deficiency. That needs to be addressed with dietary and medically guided supplementation first. Where KiriGlow™ supports the picture is by delivering Functional Keratin™ (91% bio-identical to human hair keratin), Zinc, Copper, and OptiMSM™ directly to the follicle system, supporting the structural and enzymatic environment that healthy hair growth relies on.

  • How much shedding is considered normal?

    The American Academy of Dermatology considers 50 to 100 hairs per day a normal range for people with healthy hair density. During periods of low ferritin, telogen effluvium can significantly increase this, with diffuse shedding across the scalp that persists until stores are restored. If shedding is substantially above that range and has lasted more than 8 weeks, it is worth investigating with a blood panel.

  • Should I take an iron supplement if I think my ferritin is low?

    Only if confirmed by a blood test and under the guidance of a healthcare provider. Over-supplementing iron in people with normal levels can cause oxidative damage and serious harm. Iron supplementation is not a self-prescribe situation. The right step is testing first, then acting on the actual result with medical support.

  • Can I use KiriGlow™ alongside iron supplements?

    KiriGlow™ does not contain iron and its ingredients are not known to interfere with iron supplementation. That said, if you are taking any prescribed supplement or managing a specific health condition, always check with your GP or naturopath before adding anything new to your routine. Taking KiriGlow™ at a different time of day to iron supplements is a simple, sensible precaution.

  • s the inside-out approach really necessary, or can I just eat more iron-rich foods?

    Improving iron and ferritin levels through diet is the right foundation. But if the root cause is nutritional, topical shampoos and serums alone will not reach it, and food alone may not deliver the specific building blocks that follicles need at the level required. KiriGlow™ works alongside a nutritionally sound diet to directly deliver Functional Keratin™ and the cofactors that support the hair cycle, rather than relying solely on the body's conversion pathway.

  • What makes Functional Keratin™ different from regular keratin or biotin?

    Biotin supports keratin production as an enzyme co-factor but does not provide keratin itself. Standard hydrolysed keratin is broken down through acid or heat processing into fragments too small to function as a bioactive protein. Functional Keratin™ is processed at low temperature to preserve its intact structure, meaning it is 91% bio-identical to human hair keratin and can be used by the body more effectively at follicle level. Functional Keratin™ was clinically studied to reduce shedding by up to 43% in trials.