What causes hair loss in women?
Female hair loss most often reflects iron/ferritin deficiency, thyroid dysfunction, perimenopause/menopause, postpartum hormonal shifts, or androgen excess. Ferritin and thyroid are the highest-yield first screens.
Full answer
Female hair loss is rarely a single-driver problem. The provider-reviewed workup screens iron and ferritin (the highest-yield screen in menstruating women), thyroid (TSH, Free T4, antibodies), sex hormones (estradiol, progesterone, total and free testosterone, DHEA-S, SHBG) in perimenopause and PCOS contexts, vitamin D, B12, and zinc. Postpartum telogen effluvium is common and typically self-limited. Female-pattern androgenetic alopecia exists and is treatable, but reversible causes should be ruled out first.
Educational. Not a substitute for individualized provider review.
- Ferritin — Primary source · oMeds
- Reviewed by Dr. Laura Purdy, MD, MBA · Clinical Director, oMeds · Last reviewed 2026-05-29