Does iron deficiency cause hair loss?

“I was tired and dizzy sometimes, so I thought I was anemic, but my hair was also falling out a lot.”

When treating female hair loss patients, many of them also complain of chronic fatigue, dizziness, lethargy, and headaches. This is a representative signal that appears when our body lacks iron, and has a very deep connection with hair loss. Although many people think of anemia and hair loss as separate problems, scientific studies clearly show that the two are closely linked.

1. Scientific basis: Correlation between iron deficiency and hair loss

Iron is a key component of hemoglobin in red blood cells, which carries oxygen to every cell in our body. If there is a lack of iron, the hair follicles that produce hair may not receive oxygen and nutrients properly, which can lead to hair loss. Several studies have confirmed that patients with female pattern baldness and telogen effluvium have significantly lower body iron stores (ferritin levels) compared to healthy people. In particular, the state of 'iron deficiency without anemia', in which the general anemia test (hemoglobin) is normal but the ferritin level is low, has also been found to be an important risk factor for hair loss.

2. What is Ferritin and why is it important?

Regarding hair loss, what we need to pay attention to is not only the general anemia level (hemoglobin), but also the 'Ferritin' level. Ferritin refers to the ‘iron stored in our body’. If hemoglobin in the blood is like ‘cash in your wallet’ that must be used immediately, ferritin is like ‘deposits in a bank account’ that can be used in emergencies. When our body becomes deficient in iron, it first uses ferritin stored in hair follicles, which are less important areas for sustaining life. As a result, the hair follicles become iron depleted and cannot complete the growth phase and enter the resting phase.

3. The trap of ‘normal levels’: Low normal is not normal.

Many patients are relieved to hear that “ferritin levels are within the normal range” after a blood test. However, the normal range of ferritin in blood tests is very wide, approximately 10 to 150 ng/mL. From a hair health perspective, a ferritin level of 15 or 20 is considered 'low normal' and is simply insufficient for healthy hair growth. Clinically, I believe that for healthy hair growth, ferritin levels must be maintained at least 50 ng/mL.

4. How should I supplement iron and ferritin?

If your levels are already low, it is best to quickly replenish them through nutritional supplements or injections. To increase ferritin levels, you must take iron supplements. Since the required dosage varies depending on the individual's degree of deficiency, you must consult a doctor or pharmacist. The dosage for treatment is often 100 mg to 200 mg per day based on pure iron. You must take iron supplements consistently for at least 3 to 6 months to normalize your blood levels and sufficiently replenish ferritin, the 'iron storehouse'.

5. Will my hair grow back if I just take iron supplements?

If iron deficiency is the ‘only’ cause of hair loss, you can see good results just by taking iron supplements. However, most female hair loss patients often suffer from a combination of factors such as stress, hormonal changes, and scalp inflammation, in addition to iron deficiency. Therefore, if your iron or ferritin levels are low in a blood test, it should be corrected, but in order to regain lost hair and make thinning hair thick and healthy, you must combine iron supplementation with active hair loss treatment that restores the function of weakened hair follicles and addresses other root causes.