Biotin probably isn’t
your answer. Your ferritin
number might be.
Why is my hair falling out? Search it and every source blames something different — biotin, stress, genes, your shampoo. The honest answer is that hair fall has a few distinct causes that need completely different responses. The most-marketed nutrient, biotin, has the thinnest evidence. Iron matters more — especially for Indian women — but even there, a blood test beats a guess.
Worth saying first: patchy, sudden or rapidly worsening hair loss, or hair loss with scalp itching, scaling or pain, needs a dermatologist — not a supplement.
Why is my hair falling out? Three causes to tell apart
Most hair falling out traces to one of three groups: genetic pattern hair loss (gradual, patterned, not fixed by nutrition), shedding after stress or illness (sudden, all-over, usually temporary), or a nutrient or medical cause such as low iron or thyroid disease (testable and often correctable). The pattern and timing are the best clues.
Losing 50–100 hairs a day is normal. What matters is a change — more on the pillow, a wider parting, a thinner ponytail. Think of the 28-year-old man whose hairline is creeping back, the new mother shedding handfuls three months after delivery, or the woman whose hair thinned after months of heavy periods. Their hair is falling out for three different reasons, and what helps each of them is different too.
Genetic hair loss: the most common cause
Androgenetic alopecia — male or female pattern hair loss — is inherited sensitivity to the hormone DHT, which gradually shrinks follicles. Men lose hair at the temples and crown; women thin along the parting. Nutrition doesn’t reverse it, but proven treatments exist, so see a dermatologist.
Pattern hair loss is the most common cause of all. Follicles sensitive to DHT slowly shrink, producing finer, shorter hairs until some stop growing.1 In men it shows at the temples and crown; in women, as a widening parting with the front hairline usually kept. No supplement reverses this process — but dermatologist-prescribed treatments can slow or partly reverse it, and they work best when started early.
Stress, illness and childbirth: the delayed shed
Telogen effluvium is sudden, all-over shedding that starts two to three months after a trigger — high fever, dengue or COVID, surgery, childbirth, crash dieting or severe stress. It usually settles within about six months once the trigger has passed. If it lasts longer, look for an ongoing cause.
Hair grows in cycles. A shock to the body can push many follicles into the resting phase at once, and those hairs fall out two to three months later.2 Common triggers include high fever (dengue, typhoid, COVID), surgery, childbirth, crash diets and severe emotional stress. That delay is why people rarely connect the shedding to its cause.
The good news: acute shedding usually settles within about six months once the trigger has passed, and the hair regrows. Shedding that goes on longer is called chronic telogen effluvium and deserves a look for an ongoing cause — low iron, thyroid problems or a restrictive diet.2
Other hair fall causes worth checking
Thyroid problems, PCOS, alopecia areata (round bald patches), scalp infections and some medicines can all cause hair loss. These need a doctor’s diagnosis rather than a supplement.
Needs a doctor
- Thyroid disorders — both under- and over-active can cause diffuse hair loss3
- PCOS — excess androgens can cause pattern thinning in women
- Alopecia areata — smooth, round bald patches
- Scalp conditions — itching, scaling, redness or pain
- New medicines, or stopping hormonal contraception
Clues that point to nutrition
- Heavy periods, pregnancy or recent childbirth
- A vegetarian or restrictive diet low in iron or protein
- Rapid weight loss or a crash diet
- Tiredness, breathlessness or pale skin alongside the hair fall
Biotin for hair: why the evidence is so thin
A review found only 18 published cases where biotin helped hair or nails — every one had an underlying deficiency or disorder. There’s no good evidence it helps people with normal biotin levels. High-dose biotin (5,000 mcg and above) can also distort thyroid and heart blood tests.
Biotin is the most-marketed hair nutrient, and the evidence is the thinnest. A review of the medical literature found only 18 reported cases of biotin improving hair or nails — and every one had an underlying cause, such as an inherited disorder or true deficiency. The authors found no evidence for supplementing healthy people.4 A 2023 JAMA Dermatology review of hair supplements didn’t list biotin among the interventions with good evidence.5
You may see a claim that 38% of women with hair loss are biotin deficient. That comes from one retrospective clinic study of 541 women, where many had other factors such as antibiotic use or skin conditions, and which was supported by a supplement company. It tested no treatment.6
Many “hair, skin and nails” products contain 5,000–10,000 mcg of biotin. At these doses biotin can make common blood tests read falsely — including thyroid tests and the troponin test used to diagnose heart attacks. The US FDA has issued safety warnings about this.7 Always tell your doctor or lab if you take biotin before a blood test.
Iron deficiency hair loss: real, but more nuanced
Several studies link low ferritin (stored iron) to hair loss in women, though a large controlled study found no difference. There’s no agreed “hair-healthy” ferritin level. With 57% of Indian women anaemic, a ferritin test is worth asking for — but take iron only if a test shows you need it.
Iron is where the evidence is more interesting — and more honest than most articles admit. Women with hair loss had lower ferritin than those without in several studies: in one, women with pattern hair loss averaged 49 µg/L against 78 µg/L in women without.8,9 But a large controlled study found no significant difference in iron status — and low ferritin was common in women without any hair loss.10
You’ll often read that hair needs a ferritin of 50–70. A major review found the iron–hair link plausible, but no treatment threshold has been established.11 The WHO defines iron deficiency as ferritin below 15 µg/L in healthy adults, or below 70 when inflammation is present.12 A dermatologist can interpret your number in context.
Why this matters in India: 57% of women aged 15–49 are anaemic, against 25% of men.13 If you’re a woman with hair fall, a ferritin test is worth asking for. But don’t take iron blindly — excess iron is harmful, anaemia isn’t always caused by iron deficiency, and true deficiency needs a doctor-guided dose far higher than any multivitamin contains.
“A normal iron test and a ferritin level worth discussing can be the same result. Ask for the number, not just ‘normal’.”
Why the report card isn’t the whole story
Vitamins for hair fall: what else matters
Zinc had some of the better evidence in a 2023 review of hair supplements; low vitamin D has been linked to several types of hair loss, though supplement evidence is weak. Adequate protein matters. Too much vitamin A, vitamin E or selenium can itself cause hair loss.
Zinc deficiency can cause shedding and thinning, and zinc was among the supplements with higher-quality evidence of benefit in the 2023 JAMA Dermatology review. Low vitamin D has been linked to alopecia areata, pattern hair loss and telogen effluvium, but evidence that supplementing helps hair is low-quality.5 Hair is made mostly of keratin, a protein, so adequate protein matters too — a common gap in Indian vegetarian diets.
More is not better: excess vitamin A, vitamin E and selenium can cause hair loss.5 Be wary of hair supplements stacking high doses of these. See our guide to the best form of zinc for more.
No megadoses, no blind iron — and no hair-regrowth promises.
Neither product treats hair loss. Both are built to avoid the mistakes above: no megadose biotin, no hidden iron, no vitamin A or selenium overloads.
Bioactive Multivitamin
40 mcg of biotin — a normal daily amount, not a lab-test-distorting megadose — with vegan D3, methylcobalamin B12 and active B6. Iron-free by design, so iron can be decided on a blood test. Biotin contributes to the maintenance of normal hair.
See the multivitamin →Element 5
13 mg of zinc as bisglycinate, balanced with copper at 10:1 — zinc contributes to the maintenance of normal hair — plus 300 mg of magnesium.
See Element 5 →What to do if your hair is falling out
See a dermatologist for patchy, sudden or scalp-related loss. Note the pattern and anything that happened two to three months before. Ask for ferritin, thyroid and vitamin D tests, tell the lab about any biotin, and give changes three to six months.
- See a dermatologist for red flagsPatchy, sudden or rapidly worsening loss, or itching, scaling or pain on the scalp, needs a proper diagnosis.
- Notice the pattern and the timingPatterned thinning suggests genetics; all-over shedding two to three months after an illness, childbirth or crash diet suggests telogen effluvium.
- Ask for the right testsFerritin with the actual number, a complete blood count, thyroid function and vitamin D are a sensible starting set.
- Tell the lab about biotinHigh-dose biotin can distort thyroid and heart tests; your doctor may ask you to pause it beforehand.
- Give it three to six monthsHair grows about 1 cm a month, and hairs already set to shed will still fall before new growth shows.
Hair fall, answered plainly.
Why is my hair falling out suddenly?
Does biotin help hair growth?
Can biotin affect blood tests?
Does iron deficiency cause hair loss?
What ferritin level is good for hair?
Should I take iron for hair fall?
Can vitamins fix genetic hair loss?
Which vitamins are good for hair fall?
Can thyroid problems cause hair fall?
How long does it take for hair to grow back?
Studies behind this guide
- Ho CH, Sood T, Zito PM. Androgenetic alopecia. StatPearls [Internet]. NCBI Bookshelf NBK430924.
- Malkud S. Telogen effluvium: a review. J Clin Diagn Res. 2015;9(9):WE01–3. PMC4606321.
- Vincent M, Yogiraj K. A descriptive study of alopecia patterns and their relation to thyroid dysfunction. Int J Trichology. 2013;5(1):57–60. PMC3746235.
- Patel DP, Swink SM, Castelo-Soccio L. A review of the use of biotin for hair loss. Skin Appendage Disord. 2017;3(3):166–9. PMID 28879195 — 18 reported cases, all with an underlying cause.
- Drake L, Reyes-Hadsall S, Martinez J, et al. Evaluation of the safety and effectiveness of nutritional supplements for treating hair loss: a systematic review. JAMA Dermatol. 2023;159(1):79–86. PMID 36449298 — 30 studies.
- Trüeb RM. Serum biotin levels in women complaining of hair loss. Int J Trichology. 2016;8(2):73–7. PMID 27601860 — retrospective, n=541; supported by Merz Pharma (disclosed in PMID 30410913).
- US Food and Drug Administration. Safety communication: biotin (vitamin B7) can interfere with lab tests. 2017, updated 2019.
- Park SY, Na SY, Kim JH, Cho S, Lee JH. Iron plays a certain role in patterned hair loss. J Korean Med Sci. 2013;28(6):934–8. PMID 23772161 — ferritin 49.3 vs 77.9 µg/L.
- Kantor J, Kessler LJ, Brooks DG, Cotsarelis G. Decreased serum ferritin is associated with alopecia in women. J Invest Dermatol. 2003;121(5):985–8. PMID 14708596
- Olsen EA, Reed KB, Cacchio PB, Caudill L. Iron deficiency in female pattern hair loss, chronic telogen effluvium, and control groups. J Am Acad Dermatol. 2010;63(6):991–9. PMID 20947203 — no significant difference vs controls.
- Trost LB, Bergfeld WF, Calogeras E. The diagnosis and treatment of iron deficiency and its potential relationship to hair loss. J Am Acad Dermatol. 2006;54(5):824–44. PMID 16635664
- World Health Organization. WHO guideline on use of ferritin concentrations to assess iron status in individuals and populations. Geneva; 2020 — deficiency <15 µg/L in healthy adults, <70 µg/L with inflammation.
- Ministry of Health and Family Welfare, IIPS. National Family Health Survey (NFHS-5), 2019–21 — anaemia in 57.0% of women and 25.0% of men aged 15–49.