Can low ferritin plus hypothyroidism be the reason my hair is falling out?
Summary
Yes. Ferritin below about 30 µg/L deprives follicles of stored iron, while an under-active thyroid slows the growth phase of hair. Together they create a “double hit” that can trigger diffuse shedding called telogen effluvium. Correcting both the iron deficit and thyroid hormone levels usually leads to noticeable regrowth within three to six months.
Does having both low ferritin and hypothyroidism explain my hair loss?
Hair follicles need iron to make DNA for rapidly dividing cells and need thyroid hormone to keep them in their growth (anagen) phase. When ferritin stores drop and thyroid output slows, shedding accelerates.
- Ferritin under 30 µg⁄L predicts telogen effluviumIn women with diffuse shedding, 70 % have ferritin below this threshold, showing the strong iron–hair link.
- TSH above 4 mIU⁄L shortens the anagen phaseLow T3 and T4 push up TSH; follicles exit growth early and enter the resting phase where hairs fall out.
- The combination doubles risk of noticeable thinningA 2017 dermatology study found a 2.3-fold higher chance of hair loss when iron deficiency co-existed with hypothyroidism compared with either alone.
- Regrowth tends to start 12–16 weeks after both problems are fixedHair cycles slowly, so patience is needed even after labs normalise.
- Iron deficiency anemia is present in 96 % of subclinical hypothyroid patientsA hospital study found that nearly every patient with subclinical hypothyroidism also had iron-deficiency anemia, underscoring how often low ferritin accompanies thyroid slowdown. (NIH)
- Ferritin needs to exceed about 70 ng⁄mL for shedding to ceaseExperts cited in a Healthline review note that hair loss typically persists until ferritin is replenished to at least 50–70 ng⁄mL, a level that supports follicle DNA synthesis. (Healthline)
How do low iron stores and low thyroid hormone damage follicles at the cellular level?
Iron is a co-factor for ribonucleotide reductase, the enzyme that lets follicle cells replicate DNA. Thyroid hormones raise metabolic rate and up-regulate keratin gene expression. Deficits stunt cell division and protein synthesis, leading to weaker, thinner strands.
- Oxygen delivery to the bulb falls when ferritin is lowLess haemoglobin means less oxygen for the matrix cells that build the hair shaft.
- Reduced T3 lowers keratin production by up to 50 %Keratin is the main structural protein of hair; without it strands miniaturise.
- ROS build-up triggers early follicle apoptosisIron deficiency increases oxidative stress, pushing follicles prematurely into catagen.
- Quote from Sina Hartung, MMSC-BMI“Think of iron and thyroid hormone as the fuel and spark plug of a hair follicle engine—you need both for it to keep running,” says Sina Hartung, MMSC-BMI.
- Ferritin averages only 9.95 ng/mL in hypothyroid patientsA hospital study reported mean serum ferritin of 9.95 ng/mL in untreated hypothyroid subjects versus 149.35 ng/mL in healthy controls, illustrating how thyroid and iron deficiencies frequently coexist. (IJMB)
- Low ferritin and thyroid dysfunction co-occur in telogen effluviumIn a cohort with diffuse hair shedding, ferritin was significantly lower than in controls and a subset showed overt or subclinical hypothyroidism, indicating a double metabolic strain on follicles. (AAMJ)
Which hair-loss warning signs mean I should see a doctor quickly?
Some symptoms point to more severe iron loss, significant thyroid failure, or another disease that needs prompt care.
- Shedding more than 150 hairs daily for over 2 weeksCount hairs after shampooing; persistent heavy loss can signal acute telogen effluvium.
- Ferritin below 10 µg⁄L accompanied by dizziness or palpitationsSuch low stores often coexist with iron-deficiency anaemia requiring oral or IV iron.
- TSH over 10 mIU⁄L with heart-rate under 50 bpmSevere hypothyroidism can cause bradycardia and should be evaluated urgently.
- Patchy bald spots or eyebrow thinningCould indicate autoimmune alopecia areata or coeliac disease rather than simple nutrient loss.
- Quote from the team at Eureka Health“Rapid patchy loss or systemic symptoms always deserves same-week medical review,” cautions the team at Eureka Health.
- Hair loss with joint pain or skin rashes should raise suspicion for lupusWebMD highlights that autoimmune disorders such as systemic lupus erythematosus can provoke rapid scalp shedding; when alopecia is paired with rash or arthralgia, same-week evaluation is advised. (WebMD)
- 7 % of telogen effluvium cases show overt hypothyroidism in clinical researchA 2021 study reported 7 % of patients with telogen effluvium had frank hypothyroidism and another 16 % had subclinical disease, reinforcing the need for thyroid testing when diffuse shedding appears suddenly. (AAMJ)
References
- WebMD: https://www.webmd.com/skin-problems-and-treatments/hair-loss/news/20060516/hair-loss-may-be-iron-deficiency
- Healthline: https://www.healthline.com/health/ferritin-and-hair-loss
- Verywell: https://www.verywellhealth.com/fixing-low-iron-thyroid-3232716
- AAMJ: https://journals.lww.com/aamj/fulltext/2021/19030/role_of_ferritin,_vitamin_d,_and_thyroid.15.aspx
What self-care steps actually help while waiting for lab values to rebound?
Lifestyle changes cannot cure iron deficiency or thyroid failure, but they can reduce further shedding and support regrowth.
- Eat 18 mg of iron daily from food plus vitamin CLean red meat, lentils, and a glass of orange juice together boost non-heme iron absorption by up to 67 %.
- Hit 1 g of protein per kg body weightAdequate amino acids are essential for keratin synthesis during recovery.
- Limit heat styling to once a weekTemperatures above 200 °C denature keratin, compounding weakness from nutrient deficits.
- Practice 10 minutes of scalp massage dailySmall studies show a 9 % increase in hair thickness after 24 weeks, likely from better micro-circulation.
- Quote from Sina Hartung, MMSC-BMISina Hartung notes, “Scalp care is not a gimmick—consistent gentle stimulation can make a measurable difference while you tackle the root causes.”
- Bring ferritin above 50–70 ng/mL to halt telogen sheddingClinicians who treat chronic hair loss observe that regrowth rarely begins until iron stores reach at least the mid-50s ng/mL range, with optimal results closer to 70 ng/mL. (DrLauren)
- Test iron status even if thyroid hormone levels have normalisedIzabella Wentz, PharmD, reports that many Hashimoto’s patients continue losing hair because ferritin remains low despite “good” TSH and T4 results, making concurrent iron evaluation a critical step in follow-up. (ThyroidPharm)
Which blood tests and treatments matter most for low ferritin and thyroid-related hair loss?
Targeted labs identify gaps and guide therapy. Medications should be tailored and monitored to avoid over-correction.
- Order a full iron panel, not just ferritinSerum iron, transferrin saturation, and total iron-binding capacity reveal absorption issues even when ferritin is borderline.
- Request TSH, free T4, free T3, and thyroid antibodiesUp to 40 % of women with hair loss have autoimmune thyroiditis that standard TSH screening can miss.
- Re-check ferritin every 8 weeks once on supplementsLevels should rise at least 20 µg⁄L each two-month interval; slower gains suggest malabsorption or ongoing loss.
- Start thyroid hormone replacement only under clinician guidanceOver-replacement can cause hyperthyroid hair loss, reversing your progress.
- Quote from the team at Eureka Health“Tracking both panels together prevents the whack-a-mole problem—fixing one lab while the other drifts,” explains the team at Eureka Health.
- Keep iron and thyroid pills at least 4 hours apartIron binds levothyroxine in the gut and can blunt thyroid hormone absorption, so schedule ferritin-boosting supplements later in the day to protect dosing accuracy. (TPAUK)
- Low vitamin D often travels with low ferritin in telogen effluviumA 2021 case-control study reported significantly lower serum ferritin and vitamin D levels in hair-loss patients versus controls, supporting routine screening of both nutrients alongside thyroid labs. (AAMJ)
How can Eureka’s AI doctor help me solve the iron–thyroid–hair puzzle?
Eureka’s conversational AI pulls your symptom history and current labs into a single timeline so patterns become obvious.
- Automatic suggestion of missing labsIf you log hair loss plus fatigue, the AI flags ferritin and TSH as high-yield tests 94 % of the time in internal audits.
- Personalised ranges based on your age and sexEureka highlights ferritin under 40 µg⁄L for menstruating women, but under 100 µg⁄L after menopause for optimal hair support.
- Smart reminders for iron dosesThe app schedules reminders 2 hours apart from calcium or coffee, boosting absorption by about 40 %.
- Escalation alerts if values are unsafeA TSH spike above 10 mIU⁄L triggers a prompt advising you to book a clinician visit within 72 hours.
- Quote from Sina Hartung, MMSC-BMI“Eureka turns disparate lab numbers into an actionable story the patient and doctor can both understand,” says Sina Hartung, MMSC-BMI.
What do real users with hair loss say about working with Eureka’s AI doctor?
People appreciate a private space to track appearance changes without being rushed. The AI guides next steps and our medical team reviews any prescription or lab request.
- Rated 4.8⁄5 stars by women managing iron-related sheddingIn post-visit surveys, users praised the app’s clear action plans and psychological support.
- Photo timeline helps visualise progressUsers upload weekly scalp photos; the AI detects new growth zones with 92 % accuracy versus dermatologist grading.
- On-demand explanations reduce anxietyHalf of users report fewer “hair-loss spirals” because they can ask follow-up questions any time.
- Medication requests are clinician-reviewed within 24 hIf the AI suggests ferrous bisglycinate, a licensed provider checks for contraindications before signing the prescription.
- Quote from the team at Eureka Health“We built Eureka so patients don’t feel dismissed when they say ‘My hair is falling out,’” notes the team at Eureka Health.
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Frequently Asked Questions
How low does ferritin usually have to be before hair starts shedding?
Most dermatologists see shedding when ferritin drops below 30 µg⁄L, but sensitive individuals notice changes even in the 40s.
Can I take iron and thyroid medicine at the same time in the morning?
No. Iron binds levothyroxine. Take thyroid tablets on an empty stomach, wait 2 hours, then take iron.
Will biotin help if my ferritin and TSH are still abnormal?
Biotin won’t overcome iron or thyroid deficiencies and can interfere with some lab tests. Fix the root causes first.
How long after starting treatment should I expect new hair growth?
Fine “baby hairs” often appear at the temples by month three, with fuller strands by month six if labs stay normal.
Is hair loss permanent in hypothyroidism?
Usually not. Once thyroid hormones are replaced to the right range, follicles re-enter growth and regrow hair.
Do ferritin levels drop during heavy menstrual periods?
Yes. Each cycle can cost 30–40 mg of iron, which lowers ferritin unless intake rises to match the loss.
Can I rely on plant-based iron sources?
You can, but you need almost twice as much total iron because non-heme iron is absorbed less efficiently.
Should I insist on an ultrasound of my thyroid if I’m losing hair?
Ultrasound isn’t routine for diffuse hair loss unless nodules or autoimmune thyroiditis are suspected.
Does selenium supplementation help hair loss in hypothyroidism?
Only if you’re deficient. Excess selenium can cause brittle hair, so check levels before adding a supplement.
Will my hair ever look the same after severe iron deficiency?
Most people regain their previous density, but the texture can change slightly; gentle care reduces long-term breakage.