Iron deficiency commonly worsens during perimenopause because menstrual cycles often become heavier and more irregular before they end. After menopause, iron loss decreases and ferritin typically rises, but postmenopausal iron deficiency still occurs and should be evaluated rather than assumed.

In perimenopause

• Cycles can shorten, lengthen, or become unpredictable

• Heavy menstrual bleeding (menorrhagia) often increases

• The combination of higher loss and inconsistent intake can deplete stores faster than in earlier reproductive years

• Symptoms of iron deficiency can blur with perimenopausal symptoms — fatigue, brain fog, sleep disruption, mood changes

In menopause and beyond

• Iron needs drop substantially once menstruation ends

• Ferritin tends to rise

• New-onset iron deficiency in postmenopausal women warrants evaluation for GI bleeding, malabsorption (celiac disease, IBD, H. pylori), or dietary insufficiency

For a deeper look at this life stage, see Libré's Menopause 101 guide on getlibre.co/journal.

Iron deficiency and hair loss in women

Low ferritin has been associated with telogen effluvium — a diffuse hair shedding pattern in which more hairs than usual enter the resting phase. Many dermatologists and women's-health clinicians evaluate ferritin in women with new or persistent shedding, and improvements in hair density often follow restoration of iron stores by several months.

Key points

• Hair growth is metabolically demanding; iron is needed by the follicles' rapidly dividing cells

• Telogen effluvium typically appears as diffuse thinning across the scalp, not patchy

• Shedding can start 2–3 months after the trigger (iron drop, illness, postpartum, weight loss)

• Recovery is typically gradual — visible improvement often takes 3–6 months

• Iron is not the only driver; thyroid issues, postpartum hormone shifts, stress, and androgenetic alopecia can co-exist

A clinical evaluation is appropriate when shedding is sudden, severe, or persistent (Yale Medicine).