Does iron help with hair thinning during perimenopause?

Iron is one of the most clinically relevant nutrients to check when hair thinning starts during perimenopause. Research specifically links low ferritin to hair loss in women, and this is one of the areas where the iron connection is strongest and best documented. That said, testing before supplementing is essential because hair thinning has multiple causes, and iron only helps when deficiency is actually confirmed.

Iron is required for cell division, and hair follicles are among the fastest-dividing cells in the body. Follicle cells in the matrix, the region that drives hair shaft production, have a high demand for iron at every growth cycle. When ferritin, the storage form of iron, falls below a functional threshold, follicle cells may not divide efficiently, and more hairs shift prematurely into the resting phase and then shed. This process is called telogen effluvium, and low iron is a well-documented trigger for it in women.

The research here is more specific than for many other symptoms. A study by Rushton and colleagues published in the Journal of Dermatology (2002) found that ferritin below 70 ng/mL was significantly associated with diffuse hair loss in women. This threshold is much higher than the 12 ng/mL that many standard lab reports accept as the lower limit of normal. Other researchers have noted that dermatologists often use a ferritin target of 70-80 ng/mL when evaluating iron-related hair loss, not just the absence of clinical anemia. Hemoglobin can be completely normal while ferritin is low enough to affect hair follicle function in a meaningful way.

Perimenopause adds complexity because hormonal changes also drive hair thinning independently of iron. As estrogen declines, hair follicles may become more sensitive to androgens, leading to diffuse thinning across the scalp. This androgenic mechanism happens regardless of iron status. In practice, many perimenopausal women have both low ferritin and hormonal hair loss running simultaneously, which compounds the shedding. Addressing iron deficiency is important, but it may only partially improve thinning if hormonal factors are also contributing. A full picture from your provider helps separate the causes.

To evaluate iron's role, ask your provider for ferritin, serum iron, total iron-binding capacity (TIBC), transferrin saturation, and a complete blood count (CBC). Request the actual ferritin number and compare it to the 70 ng/mL threshold rather than simply accepting a report that says the result is within normal limits. Your provider may also check thyroid function, since hypothyroidism is another common cause of hair loss that frequently overlaps with perimenopause and can be easily missed.

Never supplement with iron without a confirmed deficiency from a blood test (ferritin, serum iron, complete blood count). Iron toxicity from unnecessary supplementation is dangerous.

Iron supplements commonly cause constipation, nausea, and GI discomfort. Taking iron with vitamin C improves absorption. Avoid taking iron at the same time as calcium supplements, dairy, green tea, or coffee as these reduce absorption.

Iron interacts with many medications including thyroid medications, certain antibiotics (quinolones, tetracyclines), and bisphosphonates. Tell your provider about all medications before starting iron.

Hair responds slowly to any treatment, and iron is no exception. Even after ferritin levels are restored, it may take 3-6 months before new hair growth becomes visible, because the follicle cycle from activation to an emerging strand is lengthy. Shedding may actually continue or briefly worsen at the start of supplementation before improving, which is a normal part of the cycle resetting. Retest ferritin at 8-12 weeks to confirm levels are rising, and give any regrowth at least 6 months to assess properly. Managing expectations early helps avoid discouragement.

See your doctor if hair loss is rapid, patchy rather than diffuse, or accompanied by bald spots, scalp scaling, or redness. Patchy loss may suggest alopecia areata, an autoimmune condition that requires different evaluation and treatment. If hair loss is accompanied by significant fatigue, feeling cold all the time, constipation, or unexplained weight change, thyroid testing is particularly important alongside iron. A dermatologist referral is worthwhile if hair loss is significant or not improving after several months of treating a confirmed deficiency.

Tracking your hair shedding day by day, alongside your cycle and any supplements, gives you and your provider a clearer picture of trends over time. The PeriPlan app (https://apps.apple.com/app/periplan/id6740066498) lets you log hair thinning daily so you can spot whether patterns shift over time.

This content is for informational purposes only and does not replace medical advice. Always consult your healthcare provider about your specific situation.