Will iron regrow my hair?

Only if you are iron deficient. The review evidence supports correcting documented deficiency and does not support supplementation in people who are replete.

Ferritin together with a full blood count. Ferritin can be low while haemoglobin is still normal.

How long until I see a difference?

Shedding usually settles first, with visible density improving over six to twelve months as follicles re-enter the growth phase.

For confirmed deficiency, around 65 mg of elemental iron, often better absorbed on alternate days than daily.

Not without a deficiency, which is rare. The same review found no good evidence for biotin stimulating hair growth in replete people.

Is it safe to just try iron?

No. Iron accumulates, is dangerous in haemochromatosis, and unexplained deficiency can signal gastrointestinal bleeding that needs investigating.

Outcome

Strong Evidence

Effectiveness 4/5

Iron for Hair Follicle Stimulation

Iron deficiency is a common and reversible cause of diffuse hair shedding, and correcting low ferritin restores normal follicle cycling.

Overview

Verdict

Strong yes

Evidence supports correcting documented iron deficiency in hair loss; there is no good evidence that iron or routine micronutrient supplementation stimulates hair growth in people without deficiency.

How It Works

Downstream effects

Ribonucleotide reductase requires iron for DNA synthesis

Hair matrix cells are among the fastest dividing in the body

Iron shortage deprioritises hair before it affects haemoglobin

Follicles shift prematurely from anagen to telogen

Shedding appears 2-3 months after the trigger

Regrowth follows the follicle cycle, not the blood test

Dosing & Protocol

Doses used clinically

Situation	Dose	Schedule	Notes
Confirmed iron deficiency	65 mg elemental iron	Once daily or alternate days	Alternate-day dosing improves absorption by lowering hepcidin
Ferrous sulfate tablet	325 mg salt	Provides about 65 mg elemental iron	The standard and cheapest preparation
Poor tolerance	Ferrous bisglycinate 25-30 mg elemental	Once daily	Gentler on the gut, often adequate for mild deficiency
No documented deficiency	None	-	Iron does not stimulate hair growth in replete individuals and risks overload

Take with vitamin C or orange juice to improve absorption. Do not supplement iron without a ferritin and full blood count result.

Simple protocol

1
Get tested before anything else
Ferritin plus a full blood count. Iron supplementation without documented deficiency is not supported and is not risk free.
2
Find out why iron is low
Heavy periods, poor intake, coeliac disease and gastrointestinal blood loss all need addressing at source.
3
Take 65 mg elemental iron on alternate days· 3 months, then retest
Alternate-day dosing absorbs better than daily dosing and is gentler.
4
Take it with vitamin C, away from tea and calcium
Tea, coffee, calcium and antacids all substantially reduce absorption.
5
Expect the timeline to be slow
Shedding settles first, visible density follows over 6-12 months as follicles re-enter anagen.
6
See a clinician if hair loss continues
Thyroid disease, androgenetic alopecia and scarring alopecias need different treatment entirely.

Evidence

Studies linked to this pairing.

The Role of Vitamins and Minerals in Hair Loss: A Review

Score: 6/10

2019

systematic_review

Almohanna HM, Ahmed AA, Tsatalis JP +1 more

Deficiency of such micronutrients may represent a modifiable risk factor associated with the development, prevention, and treatment of alopecia.

View source

Supported use: Correcting documented iron deficiency
Not supported: Routine supplementation in people without deficiency
Biotin: No good evidence for hair growth without deficiency
Marker to test: Ferritin, alongside a full blood count
Time to visible change: Typically 6-12 months, following the follicle cycle
Main limitation: Optimal ferritin threshold for hair regrowth is debated and not firmly established

Safety

Do not take iron for hair loss without a blood test

Iron helps hair only when deficiency is documented. In replete people it does not stimulate growth and contributes to iron overload, which is dangerous in haemochromatosis.

Interactions & Conflicts

Interactions and cautions

Interacts with	Severity	Mechanism	Action
Haemochromatosis or iron overload	high	Further accumulation of iron in tissues	Avoid entirely
Levothyroxine	high	Iron binds thyroxine and reduces absorption	Separate by at least 4 hours
Tetracycline and quinolone antibiotics	high	Chelation reduces absorption of both	Separate by at least 2-4 hours
Proton pump inhibitors and antacids	moderate	Reduced gastric acid impairs iron absorption	Take iron with vitamin C and discuss with a clinician
Tea, coffee and calcium	moderate	Polyphenols and calcium inhibit non-haem iron absorption	Separate by an hour either side
Unexplained deficiency in men or postmenopausal women	high	May indicate gastrointestinal blood loss	Seek medical assessment before self-treating

References

Frequently Asked Questions

Medical Disclaimer

The information provided on this website is for educational and informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or before starting any supplement regimen.

Individual results may vary. The statements on this website have not been evaluated by the Food and Drug Administration. Products and information are not intended to diagnose, treat, cure, or prevent any disease.